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A208575
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Product of digits of n in factorial base.
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12
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0, 1, 0, 1, 0, 2, 0, 0, 0, 1, 0, 2, 0, 0, 0, 2, 0, 4, 0, 0, 0, 3, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 2, 0, 4, 0, 0, 0, 3, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 4, 0, 0, 0, 4, 0, 8, 0, 0, 0, 6, 0, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 6, 0, 0, 0, 6, 0, 12, 0, 0, 0, 9, 0, 18
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OFFSET
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0,6
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LINKS
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MATHEMATICA
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(* For the definition of the factorial base version of IntegerDigits, see A007623 *) Table[Times@@factBaseIntDs[n], {n, 0, 99}] (* Alonso del Arte, Feb 28 2012 *)
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PROG
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(PARI) a(n)=my(k=1, s=1); while(n, s*=n%k++; n\=k); s
(Python)
from operator import mul
def A(n, p=2):
return n if n<p else A(n//p, p+1)*10 + n%p
def a(n):
x=str(A(n - 1))
return 0 if "0" in x else reduce(mul, [int(i) for i in x])
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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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