Idoneal numbers: Difference between revisions
Content deleted Content added
Added Wren |
Added C# version, translated from python version, Added Pari/GP version from OEIS source |
||
Line 20:
;* [[oeis:A000926|OEIS:A000926 - Euler's "numerus idoneus" (or "numeri idonei", or idoneal, or suitable, or convenient numbers)]]
=={{header|C#|CSharp}}==
{{trans|Python}}
<syntaxhighlight lang="csharp">using System;
class Program {
static void Main(string[] args) {
var sw = System.Diagnostics.Stopwatch.StartNew();
int a, b, c, i, n, s3, ab; var res = new int[65];
for (n = 1, i = 0; n < 1850; n++) {
bool found = true;
for (a = 1; a < n; a++)
for (b = a + 1, ab = a * b + a + b; b < n; b++, ab += a + 1) {
if (ab > n) break;
for (c = b + 1, s3 = ab + (b + a) * b; c < n; c++, s3 += b + a) {
if (s3 == n) found = false;
if (s3 >= n) break;
}
}
if (found) res[i++] = n;
}
sw.Stop();
Console.WriteLine("The 65 known Idoneal numbers:");
for (i = 0; i < res.Length; i++)
Console.Write("{0,5}{1}", res[i], i % 13 == 12 ? "\n" : "");
Console.Write("Calculations took {0} ms", sw.Elapsed.TotalMilliseconds);
}
}</syntaxhighlight>
{{out}}
<pre>The 65 known Idoneal numbers:
1 2 3 4 5 6 7 8 9 10 12 13 15
16 18 21 22 24 25 28 30 33 37 40 42 45
48 57 58 60 70 72 78 85 88 93 102 105 112
120 130 133 165 168 177 190 210 232 240 253 273 280
312 330 345 357 385 408 462 520 760 840 1320 1365 1848
Calculations took 28.5862 ms</pre>
=={{header|PARI/GP}}==
Adapted from the [[oeis:A000926|OEIS:A000926]] page.
<syntaxhighlight lang="parigp">ok(n) = !#select(k -> k <> 2, quadclassunit(-n << 2).cyc) \\ Andrew Howroyd, Jun 08 2018
c = 0; for (n = 1, 1850, ok(n) & printf("%5d%s", n, if (c++ % 13 == 0, "\n", "")))</syntaxhighlight>
{{out}}
<pre> 1 2 3 4 5 6 7 8 9 10 12 13 15
16 18 21 22 24 25 28 30 33 37 40 42 45
48 57 58 60 70 72 78 85 88 93 102 105 112
120 130 133 165 168 177 190 210 232 240 253 273 280
312 330 345 357 385 408 462 520 760 840 1320 1365 1848</pre>
=={{header|Python}}==
| |||