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A367509 a(n) = Sum_{d|n} (2*d+1)^n. 3

%I #12 Nov 21 2023 09:40:23

%S 3,34,370,7267,161294,4960812,170861562,7019201348,322728071069,

%T 16705828227476,952809758091074,59628239376008854,4052555153020570590,

%U 297587425607933152700,23465266173840431204452,1978033864507607364591749,177482997121587371955312038

%N a(n) = Sum_{d|n} (2*d+1)^n.

%H Seiichi Manyama, <a href="/A367509/b367509.txt">Table of n, a(n) for n = 1..351</a>

%F a(n) = Sum_{k=0..n} 2^k * binomial(n,k) * sigma_k(n).

%o (PARI) a(n) = sumdiv(n, d, (2*d+1)^n);

%Y Cf. A163190, A367510.

%K nonn

%O 1,1

%A _Seiichi Manyama_, Nov 21 2023

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Last modified September 3 17:32 EDT 2024. Contains 375673 sequences. (Running on oeis4.)