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A328876 Dirichlet g.f.: Product_{k>=2} (1 + k^(-s))^(k + 1). 1
1, 3, 4, 8, 6, 19, 8, 25, 16, 29, 12, 66, 14, 39, 40, 69, 18, 95, 20, 102, 54, 59, 24, 220, 41, 69, 72, 138, 30, 237, 32, 191, 82, 89, 84, 379, 38, 99, 96, 342, 42, 321, 44, 210, 206, 119, 48, 679, 78, 240, 124, 246, 54, 459, 128, 464, 138, 149, 60, 971 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Number of ways to factor n into distinct factors with 3 kinds of 2, 4 kinds of 3, ..., k+1 kinds of k.
Dirichlet convolution of A045778 with A050368.
LINKS
FORMULA
a(n) = Sum_{d|n} A045778(n/d) * A050368(d).
PROG
(PARI) seq(n)={my(v=vector(n, k, k==1)); for(k=2, n, my(m=logint(n, k), p=(1 + x + O(x*x^m))^(k+1), w=vector(n)); for(i=0, m, w[k^i]=polcoef(p, i)); v=dirmul(v, w)); v} \\ Andrew Howroyd, Oct 29 2019
CROSSREFS
Sequence in context: A081307 A344225 A081543 * A105753 A292822 A255703
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Oct 29 2019
STATUS
approved

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Last modified March 29 11:45 EDT 2024. Contains 371278 sequences. (Running on oeis4.)