Erdős-primes: Difference between revisions

{{trans|Nim}}

V is_prime = [0B] * 2 [+] [1B] * (limit - 1)

L(n) 0 .< Int(limit ^ 0.5 + 1.5)

I count == 7875

print("\nThe 7875th Erdos prime is "p‘.’)

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=={{header|Action!}}==

{{libheader|Action! Sieve of Eratosthenes}}

BYTE Func IsErdosPrime(INT x BYTE ARRAY primes)

OD

PrintF("%E%EThere are %I Erdos primes",count)

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[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Erd%C5%91s-primes.png Screenshot from Atari 8-bit computer]

=={{header|ALGOL 68}}==

# returns TRUE if p is an Erdős prime #

PROC is erdos prime = ( INT p )BOOL:

OD;

print( ( newline, "Found ", whole( e count, 0 ), " Erdos primes" ) )

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<pre>

=={{header|Arturo}}==

erdos?: function [x][

if not? prime? x -> return false

loop split.every:10 select 2..2500 => erdos? 'a ->

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=={{header|AWK}}==

# syntax: GAWK -f ERDOS-PRIMES.AWK

# converted from FreeBASIC

return(1)

}

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<pre>

=={{header|C sharp|C#}}==

class Program {

const int lmt = (int)1e6, first = 2500; static int[] f = new int[10];

if (x < 4) return x > 1; if ((x & 1) == 0) return false;

for (int i = 3; i * i <= x; i += 2) if (x % i == 0) return false;

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<pre> 2 101 211 367 409

=={{header|C++}}==

{{libheader|Primesieve}}

#include <iomanip>

#include <iostream>

std::wcout << L"\n\nThe " << max_count << L"th Erd\x151s prime is " << p << L".\n";

return 0;

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=={{header|F_Sharp|F#}}==

This task uses [http://www.rosettacode.org/wiki/Extensible_prime_generator#The_functions Extensible Prime Generator (F#)]

// Erdős Primes. Nigel Galloway: March 22nd., 2021

let rec fN g=function 1->g |n->fN(g*n)(n-1)

let eP()=primes32()|>Seq.filter(fG 1>>Seq.forall id)

eP()|>Seq.takeWhile((>)2500)|>Seq.iter(printf "%d "); printfn "\n\n7875th Erdős prime is %d" (eP()|>Seq.item 7874)

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<pre>

=={{header|Factor}}==

{{works with|Factor|0.99 2021-02-05}}

math.factorials math.primes math.primes.lists math.vectors

prettyprint sequences tools.memory.private ;

7874 erdős lnth commas

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<pre>

=={{header|Forth}}==

{{works with|Gforth}}

: notprime! ( n -- ) here + 1 swap c! ;

2500 print_erdos_primes

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=={{header|FreeBASIC}}==

I won't bother reproducing a primality-testing function; use the one from [[Primality_by_trial_division#FreeBASIC]].

function is_erdos_prime( p as uinteger ) as boolean

if i<2500 or c=7875 then print c, i

end if

{{out}}<pre>1 2

2 101

=={{header|Go}}==

{{trans|Wren}}

import "fmt"

show := 7875

fmt.Printf("\n\nThe %s Erdős prime is %s.\n", commatize(show), commatize(erdos[show-1]))

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Implementation:

erdospr=: {{ k=. y

f=. !k+0 1

NB. erdos primes less than j

Task examples:

2 101 211 367 409 419 461 557 673 709 769 937 967 1009 1201 1259 1709 1831 1889 2141 2221 2309 2351 2411 2437

(#,{:) erdosprs 1e6

=={{header|Java}}==

public class ErdosPrimes {

return sieve;

}

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'''Preliminaries'''

def is_prime:

| . * . > $n

end;

'''Erdős-primes'''

def is_Erdos:

. as $p

# emit the Erdos primes

def Erdos: range(2; infinite) | select(is_Erdos);

'''The tasks'''

"\nThe 7875th Erdős prime is \(nth(7874; Erdos))."

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<pre>

=={{header|Julia}}==

function isErdős(p::Integer)

println(length(E2500), " Erdős primes < 2500: ", E2500)

println("The 7875th Erdős prime is ", format(Erdőslist[7875], commas=true))

<pre>

25 Erdős primes < 2500: [2, 101, 211, 367, 409, 419, 461, 557, 673, 709, 769, 937, 967, 1009, 1201, 1259, 1709, 1831, 1889, 2141, 2221, 2309, 2351, 2411, 2437]

=={{header|Mathematica}}/{{header|Wolfram Language}}==

ErdosPrimeQ[p_Integer] := Module[{k},

If[PrimeQ[p],

Length[sel]

sel = Select[Range[999999], ErdosPrimeQ];

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<pre>{2, 101, 211, 367, 409, 419, 461, 557, 673, 709, 769, 937, 967, 1009, 1201, 1259, 1709, 1831, 1889, 2141, 2221, 2309, 2351, 2411, 2437}

=={{header|Nim}}==

const N = 1_000_000

erdös7875 = p

break

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=={{header|Perl}}==

{{libheader|ntheory}}

use warnings;

use feature 'say';

say 'Erdős primes < ' . (my $max = 2500) . ':';

say join ' ', before { $_ > 2500 } @Erdős;

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<pre>Erdős primes < 2500:

=={{header|Phix}}==

<span style="color: #004080;">atom</span> <span style="color: #000000;">t0</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">time</span><span style="color: #0000FF;">()</span>

<span style="color: #004080;">sequence</span> <span style="color: #000000;">facts</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}</span>

<span style="color: #004080;">integer</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">)</span>

<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"The %,d%s Erdos prime is %,d (%s)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">l</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ord</span><span style="color: #0000FF;">(</span><span style="color: #000000;">l</span><span style="color: #0000FF;">),</span><span style="color: #000000;">res</span><span style="color: #0000FF;">[$],</span><span style="color: #7060A8;">elapsed</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">time</span><span style="color: #0000FF;">()-</span><span style="color: #000000;">t0</span><span style="color: #0000FF;">)})</span>

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<pre>

=={{header|Raku}}==

my @factorial = 1, |[\*] 1..*;

put 'Erdős primes < 2500:';

put @Erdős[^(@Erdős.first: * > 2500, :k)]».&comma;

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<pre>Erdős primes < 2500:

=={{header|REXX}}==

parse arg n cols . /*get optional number of primes to find*/

if n=='' | n=="," then n= 2500 /*Not specified? Then assume default.*/

end /*k*/ /* [↑] only divide up to √ J */

#= # + 1; @.#= j; !.j= 1 /*bump prime count; assign prime & flag*/

{{out|output|text=&nbsp; when using the default inputs:}}

<pre>

=={{header|Rust}}==

// primal = "0.3"

println!("\nThe 7875th Erd\u{151}s prime is {}.", p);

}

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=={{header|Sidef}}==

return true if p==2

say ("Erdős primes <= 2500: ", 1..2500 -> grep(is_erdos_prime))

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<pre>

Can't manage the stretch goal because integers are limited to signed 16 bit.

10 IF P > 2 THEN LET P = P + 2

IF P < 3 THEN LET P = P + 1

IF A=K THEN RETURN

LET A = A + 1

{{out}}<pre>1 2

2 101

{{libheader|Wren-seq}}

{{libheader|Wren-fmt}}

import "/seq" for Lst

import "/fmt" for Fmt

for (chunk in Lst.chunks(erdosLower, 10)) Fmt.print("$6d", chunk)

var show = 7875

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=={{header|XPL0}}==

int N, I;

[if N <= 2 then return N = 2;

Text(0, "The "); IntOut(0, Cnt);

Text(0, "th Erdos prime is indeed "); IntOut(0, SN); CrLf(0);

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