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A045566 Numbers n such that final 2 nonzero digits of n! are '76'. 1
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 (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, 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

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Last modified November 17 11:02 EST 2019. Contains 329226 sequences. (Running on oeis4.)