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A128212
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a(n)=sum_digits(p), where p is the product of the digits of n.
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0
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1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 2, 4, 6, 8, 1, 3, 5, 7, 9, 0, 3, 6, 9, 3, 6, 9, 3, 6, 9, 0, 4, 8, 3, 7, 2, 6, 10, 5, 9, 0, 5, 1, 6, 2, 7, 3, 8, 4, 9, 0, 6, 3, 9, 6, 3, 9, 6, 12, 9, 0, 7, 5, 3, 10, 8, 6, 13, 11, 9, 0, 8, 7, 6, 5, 4, 12, 11, 10, 9, 0, 9, 9, 9, 9, 9, 9, 9, 9, 9, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| The sequence grows very slowly. For n<=10000 the maximal value is 27.
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EXAMPLE
| a(73)=3 because 7*3=21 and 2+1=3
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MAPLE
| P:=proc(n) local i, k, w; for i from 1 by 1 to n do w:=1; k:=i; while k>0 do w:=w*(k-(trunc(k/10)*10)); k:=trunc(k/10); od; k:=w; w:=0; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; print(w); od; end: P(100);
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CROSSREFS
| Sequence in context: A062078 A031347 A087471 * A187844 A007954 A079475
Adjacent sequences: A128209 A128210 A128211 * A128213 A128214 A128215
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KEYWORD
| easy,nonn,base
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AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), May 03 2007
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