A045570 Numbers whose factorial has '96' as its final two digits before the trailing zeros.

17, 46, 60, 68, 120, 123, 160, 210, 222, 235, 240, 290, 300, 301, 360, 365, 393, 455, 477, 480, 520, 523, 525, 526, 542, 600, 601, 628, 686, 721, 752, 800, 801, 834, 841, 872, 881, 909, 911, 916, 961, 968, 984, 988, 991, 1011, 1015, 1022, 1030, 1054, 1077

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Index entries for sequences related to final digits of numbers

Mathematica

Select[Range[5, 1100], Flatten[Take[Most[Split[IntegerDigits[#!]]], -2]] == {9, 6}&] (* Harvey P. Dale, Apr 08 2012 *)

Prog

(PARI) last(n, k)=if(n*8\9-1<k, n=n!; return(n/10^valuation(n, 10)%10^k)); my(m=Mod(1, 5^k)); for(i=2, n, m*=i/10^valuation(i, 5)); lift(chinese(m, Mod(0, 2^k))) \\ Gives the last k decimal digits of n!.
is(n)=last(n, 2)==96 \\ Charles R Greathouse IV, Oct 22 2014
(PARI) is(n)=my(m=Mod(1, 25)); for(i=2, n, m*=i/10^valuation(i, 5)); m==96 \\ Charles R Greathouse IV, Oct 22 2014
(PARI) v=List(); m=Mod(1, 25); for(n=2, 1e6, m*=n/10^valuation(n, 5); if(m==96, listput(v, n); if(#v==100, return(Vec(v))))) \\ Charles R Greathouse IV, Oct 22 2014

Crossrefs

Sequence in context: A032698 A120099 A307293 * A058205 A329951 A034783

Adjacent sequences: A045567 A045568 A045569 * A045571 A045572 A045573

Keyword

nonn,base

Author

Jeff Burch

Extensions

More terms from Robert G. Wilson v, Dec 14 2000

Status

approved