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A045570 Numbers n such that final 2 nonzero digits of n! are '96'. 1
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 (list; graph; refs; listen; history; text; internal format)
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 A034783 A275770

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

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Last modified November 21 01:33 EST 2019. Contains 329349 sequences. (Running on oeis4.)