A045568 Numbers whose factorial has '88' as its final two digits before the trailing zeros.

9, 10, 16, 31, 54, 83, 94, 125, 126, 171, 186, 232, 250, 251, 279, 282, 313, 357, 412, 424, 450, 451, 462, 478, 534, 536, 541, 574, 586, 593, 610, 615, 636, 640, 647, 652, 664, 695, 698, 714, 731, 753, 795, 798, 813, 829

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Index entries for sequences related to final digits of numbers

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)==88 \\ 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==88 \\ 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==88, listput(v, n); if(#v==100, return(Vec(v))))) \\ Charles R Greathouse IV, Oct 22 2014

Crossrefs

Sequence in context: A121061 A106690 A173015 * A191380 A088036 A217935

Adjacent sequences: A045565 A045566 A045567 * A045569 A045570 A045571

Keyword

nonn,base

Author

Jeff Burch

Status

approved