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Search: id:A007954
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| A007954 |
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Product of digits of n. |
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+0
50
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| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 0, 9, 18, 27, 36, 45, 54, 63, 72, 81, 0, 0, 0, 0, 0, 0, 0, 0
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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A000035(a(A014261(n))) = 1. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 30 2007
Moebius transform of A093811(n). a(n) = A093811(n) * A008683(n), where operation * denotes Dirichlet convolution for n >= 1. Dirichlet convolution of functions b(n), c(n) is function a(n) = b(n) * c(n) = Sum_{d|n} b(d)*c(n/d). Simultaneously holds Dirichlet multiplication: a(n) * A000012(n) = A093811(n). [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Mar 22 2009]
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REFERENCES
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F. Smarandache, "Only Problems, not Solutions!", Xiquan Publ., Phoenix-Chicago, 1993
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LINKS
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N. J. A. Sloane, Table of n, a(n) for n = 0..10000
M. L. Perez et al., eds., Smarandache Notions Journal
F. Smarandache, Only Problems, Not Solutions!.
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MAPLE
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A007954 := proc(n) local t1, t2; t1 := n; t2 := 1; while t1 <> 0 do t2 := t2 * (t1 mod 10); t1 := floor(t1/10); od: t2; end;
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MATHEMATICA
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Array[ Times @@ IntegerDigits[ #-1 ]&, 100 ]
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PROGRAM
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(PARI) A007954(n)= { local(resul); if(n<10, return(n) ); resul = n % 10; n = (n - n%10)/10; while( n > 0, resul *= n %10; n = (n - n%10)/10; ); return(resul); } { for(n=0, 50, print1(A007954(n), ", "); ); } - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 23 2006
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CROSSREFS
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Cf. A031347 (different from A035930), A007953, A010888.
Cf. A093811, A008683, A000012. [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Mar 22 2009]
Sequence in context: A031347 A087471 A128212 this_sequence A079475 A081286 A080867
Adjacent sequences: A007951 A007952 A007953 this_sequence A007955 A007956 A007957
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KEYWORD
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nonn,base,easy,nice
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AUTHOR
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R. Muller
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EXTENSIONS
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Error in term 25 corrected 11/95.
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