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A067067
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Product of nonzero digits of n! (A000142).
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2
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1, 1, 2, 6, 8, 2, 14, 20, 24, 2304, 2304, 11664, 1512, 2688, 112896, 508032, 18579456, 87091200, 11854080, 368640, 6967296, 22861440, 542126592, 1872809164800, 40633270272, 559872000, 26873856000, 8561413324800, 178362777600
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OFFSET
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0,3
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LINKS
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EXAMPLE
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a(10) = 2304 as 10! = 3628800 and 3*6*2*8*8 = 2304.
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MATHEMATICA
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f[n_] := Block[{d = Sort[ IntegerDigits[n! ]] }, While[ First[d] == 0, d = Drop[d, 1]]; Return[ Apply[ Times, d]]]; Table[ f[n], {n, 0, 30} ]
Table[Times@@DeleteCases[IntegerDigits[n!], 0], {n, 0, 30}] (* Harvey P. Dale, Jan 11 2016 *)
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PROG
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(PARI) ProdNzD(x)= { local(d, p=1); while (x>9, d=x%10; if (d, p*=d); x\=10); return(p*x) } { for (n=0, 200, write("b067067.txt", n, " ", ProdNzD(n!)) ) } \\ Harry J. Smith, May 03 2010
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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