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A045555
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Numbers whose factorial has '24' as its final two digits before the trailing zeros.
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1
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4, 37, 49, 52, 58, 69, 75, 76, 87, 117, 179, 205, 277, 289, 307, 321, 339, 383, 394, 409, 411, 416, 425, 426, 461, 468, 493, 512, 546, 563, 621, 645, 648, 717, 724, 725, 726, 759, 760, 766, 780, 807, 821, 827, 831
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internal format)
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OFFSET
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1,1
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LINKS
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PROG
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(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!.
(PARI) v=List(); m=Mod(1, 25); for(n=2, 1e6, m*=n/10^valuation(n, 5); if(m==24, listput(v, n); if(#v==100, return(Vec(v))))) \\ Charles R Greathouse IV, Oct 22 2014
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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