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A051801
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Product of nonzero digits of n.
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14
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1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 2, 4, 6, 8, 10, 12, 14, 16, 18, 3, 3, 6, 9, 12, 15, 18, 21, 24, 27, 4, 4, 8, 12, 16, 20, 24, 28, 32, 36, 5, 5, 10, 15, 20, 25, 30, 35, 40, 45, 6, 6, 12, 18, 24, 30, 36, 42, 48, 54, 7, 7, 14, 21
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| Zak Seidov, Table of n, a(n) for n = 0..1000.
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FORMULA
| a(n) = if n=0 then 1 else a([n/10]) * (n mod 10 + 0^(n mod 10)). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 13 2009]
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EXAMPLE
| a(0) = 1 since an empty product is 1 by convention. a(120) = 1*2 = 2.
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MAPLE
| A051801 := proc(n) local d, j: d:=convert(n, base, 10): return mul(`if`(d[j]=0, 1, d[j]), j=1..nops(d)): end: seq(A051801(n), n=0..100); # Nathaniel Johnston, May 04 2011
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MATHEMATICA
| (Times@@Cases[IntegerDigits[#], Except[0]])&/@Range[0, 80] (* From Harvey P. Dale, June 20 2011 *)
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PROG
| (Haskell)
a051801 0 = 1
a051801 n = (a051801 n') * (m + 0 ^ m) where (n', m) = divMod n 10
-- Reinhard Zumkeller, Nov 23 2011
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CROSSREFS
| Basis for A051802.
Sequence in context: A067456 A052429 A051802 * A071205 A066750 A032762
Adjacent sequences: A051798 A051799 A051800 * A051802 A051803 A051804
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KEYWORD
| nonn,easy,base,nice
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AUTHOR
| Dan Hoey (Hoey(AT)AIC.NRL.Navy.Mil), Dec 09 1999
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