A045566 Numbers whose factorial has '76' as its final two digits before the trailing zeros.

45, 48, 65, 79, 107, 127, 175, 176, 209, 216, 247, 252, 285, 303, 312, 317, 335, 347, 372, 386, 390, 397, 405, 429, 452, 456, 481, 528, 603, 649, 688, 707, 720, 723, 729, 755, 764, 784, 786, 791, 803, 812, 817, 836, 843

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, 900], Take[Flatten[Most[Split[IntegerDigits[#!]]]], -2]=={7, 6}&] (* Harvey P. Dale, Apr 04 2013 *)

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)==76 \\ 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==76 && n>1 \\ 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==76, listput(v, n); if(#v==100, return(Vec(v))))) \\ Charles R Greathouse IV, Oct 22 2014

Crossrefs

Sequence in context: A291787 A257410 A306103 * A274368 A214572 A295493

Adjacent sequences: A045563 A045564 A045565 * A045567 A045568 A045569

Keyword

nonn,base

Author

Jeff Burch

Status

approved