Left factorials: Difference between revisions

=={{header|Go}}==

<lang go>package main

import (

"fmt"

"math/big"

)

func main() {

fmt.Print("!0 through !10: 0")

one := big.NewInt(1)

n := big.NewInt(1)

f := big.NewInt(1)

l := big.NewInt(1)

next := func() { f.Mul(f, n); l.Add(l, f); n.Add(n, one) }

for ; ; next() {

fmt.Print(" ", l)

if n.Int64() == 10 {

break

}

}

fmt.Println()

for {

for i := 0; i < 10; i++ {

next()

}

fmt.Printf("!%d: %d\n", n, l)

if n.Int64() == 110 {

break

}

}

fmt.Println("Lengths of !1000 through !10000 by thousands:")

for i := 110; i < 1000; i++ {

next()

}

for {

fmt.Print(" ", len(l.String()))

if n.Int64() == 10000 {

break

}

for i := 0; i < 1000; i++ {

next()

}

}

fmt.Println()

}</lang>

{{out}}

<pre>

!0 through !10: 0 1 2 4 10 34 154 874 5914 46234 409114

!20: 128425485935180314

!30: 9157958657951075573395300940314

!40: 20935051082417771847631371547939998232420940314

!50: 620960027832821612639424806694551108812720525606160920420940314

!60: 141074930726669571000530822087000522211656242116439949000980378746128920420940314

!70: 173639511802987526699717162409282876065556519849603157850853034644815111221599509216528920420940314

!80: 906089587987695346534516804650290637694024830011956365184327674619752094289696314882008531991840922336528920420940314

!90: 16695570072624210767034167688394623360733515163575864136345910335924039962404869510225723072235842668787507993136908442336528920420940314

!100: 942786239765826579160595268206839381354754349601050974345395410407078230249590414458830117442618180732911203520208889371641659121356556442336528920420940314

!110: 145722981061585297004706728001906071948635199234860720988658042536179281328615541936083296163475394237524337422204397431927131629058103519228197429698252556442336528920420940314

Lengths of !1000 through !10000 by thousands:

2565 5733 9128 12670 16322 20062 23875 27749 31678 35656

</pre>