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 A091828 a(n)=n-2*valuation(A000254(n),3). 0
 1, 0, 3, 4, 5, 2, 1, 4, 5, 6, 7, 6, 7, 8, 7, 8, 9, 4, 5, 6, 3, 2, 5, 6, 7, 8, 7, 8, 9, 8, 9, 10, 9, 10, 11, 8, 9, 10, 9, 10, 11, 10, 11, 12, 9, 10, 11, 10, 11, 12, 11, 12, 13, 6, 7, 8, 7, 8, 9, 8, 9, 10, 5, 6, 7, 4, 5, 6, 7, 8, 9, 8, 9, 10, 9, 10, 11, 10, 11, 12, 9, 10, 11, 10, 11, 12, 11, 12, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS FORMULA For n>7 a(3n)=a(n)+2; a(3n+1)=a(n)+3; (3n+2)=a(n)+4 PROG (PARI) a(n)=if(n<2, 1, n-2*valuation(n!*sum(i=1, n, 1/i), 3)) CROSSREFS Cf. A056792. Sequence in context: A144786 A247369 A009389 * A121845 A239639 A099816 Adjacent sequences:  A091825 A091826 A091827 * A091829 A091830 A091831 KEYWORD nonn AUTHOR Benoit Cloitre, Mar 09 2004 STATUS approved

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