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a(n) = tau(11*n) = A000005(11*n).
10

%I #6 May 13 2024 12:21:34

%S 2,4,4,6,4,8,4,8,6,8,3,12,4,8,8,10,4,12,4,12,8,6,4,16,6,8,8,12,4,16,4,

%T 12,6,8,8,18,4,8,8,16,4,16,4,9,12,8,4,20,6,12,8,12,4,16,6,16,8,8,4,24,

%U 4,8,12,14,8,12,4,12,8,16,4,24,4,8,12,12,6,16

%N a(n) = tau(11*n) = A000005(11*n).

%H Vaclav Kotesovec, <a href="/A372791/a372791.jpg">Graph - the asymptotic ratio (100000 terms)</a>

%F Sum_{k=1..n} a(k) ~ (21*n*(log(n) + 2*gamma - 1) + n*log(11)) / 11, where gamma is the Euler-Mascheroni constant A001620.

%t Table[DivisorSigma[0, 11*n], {n, 1, 150}]

%Y Cf. A000005, A099777, A372713, A372784, A372785, A372786, A372787, A372788, A372789, A372790, A372792.

%K nonn

%O 1,1

%A _Vaclav Kotesovec_, May 13 2024