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 A013938 a(n) = Sum_{k=1..n} floor(n/k^4). 1
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 OFFSET 1,2 LINKS FORMULA G.f.: (1/(1 - x))*Sum_{k>=1} x^(k^4)/(1 - x^(k^4)). - Ilya Gutkovskiy, Feb 11 2017 PROG (PARI) a(n) = sum(k=1, n, n\k^4); \\ Michel Marcus, Feb 11 2017 CROSSREFS Cf. A013936, A013937. Sequence in context: A209061 A178210 A115063 * A023809 A046100 A023757 Adjacent sequences:  A013935 A013936 A013937 * A013939 A013940 A013941 KEYWORD nonn AUTHOR STATUS approved

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Last modified February 16 05:10 EST 2019. Contains 320140 sequences. (Running on oeis4.)