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A034751 Dirichlet convolution of 3^(n-1) with itself. 1
1, 6, 18, 63, 162, 540, 1458, 4536, 13203, 39852, 118098, 356238, 1062882, 3193020, 9567396, 28711665, 86093442, 258324066, 774840978, 2324645406, 6973581924, 20921060700, 62762119218, 188287473024, 564859079523, 1694580407532 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) ~ 2 * 3^(n-1). - Vaclav Kotesovec, Sep 11 2019
G.f.: Sum_{k>=1} 3^(k-1)*x^k / (1 - 3*x^k). - Ilya Gutkovskiy, Sep 22 2020
MATHEMATICA
Table[Sum[3^(d + n/d - 2), {d, Divisors[n]}], {n, 1, 30}] (* Vaclav Kotesovec, Sep 10 2019 *)
CROSSREFS
Cf. A034719.
Sequence in context: A334330 A144706 A074427 * A200151 A000623 A304941
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified July 25 02:33 EDT 2024. Contains 374585 sequences. (Running on oeis4.)