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A045569 Numbers n such that final 2 nonzero digits of n! are '92'. 1
84, 91, 110, 115, 181, 189, 217, 224, 228, 302, 308, 319, 328, 353, 378, 404, 407, 435, 443, 518, 527, 539, 554, 589, 602, 605, 630, 639, 663, 668, 672, 675, 676, 713, 715, 736, 757, 775, 776, 792, 802, 808, 819 (list; graph; refs; listen; history; text; internal format)
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

MATHEMATICA

fndQ[n_]:=Module[{f=n!}, Take[Drop[IntegerDigits[f], -IntegerExponent[ f, 10]], -2] == {9, 2}]; Select[Range[5, 900], fndQ] (* Harvey P. Dale, Sep 26 2016 *)

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)==92 \\ 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==92 \\ 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==92, listput(v, n); if(#v==100, return(Vec(v))))) \\ Charles R Greathouse IV, Oct 22 2014

CROSSREFS

Sequence in context: A128873 A095607 A068405 * A219183 A289218 A113931

Adjacent sequences:  A045566 A045567 A045568 * A045570 A045571 A045572

KEYWORD

nonn,base

AUTHOR

Jeff Burch

STATUS

approved

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Last modified November 13 00:25 EST 2019. Contains 329083 sequences. (Running on oeis4.)