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%I #12 Sep 11 2019 05:27:22
%S 4,16,32,80,128,320,512,1152,2112,4352,8192,17152,32768,66560,131584,
%T 264448,524288,1053696,2097152,4203520,8390656,16793600,33554432,
%U 67147776,134218752,268500992,536879104,1073876992,2147483648
%N Dirichlet convolution of powers of 2 (2,4,8,...) with themselves.
%F a(n) = 4 * A034733(n).
%F G.f.: Sum_{k>=1} 2^(k+1)*x^k/(1 - 2*x^k). - _Ilya Gutkovskiy_, Sep 10 2019
%F a(n) ~ 2^(n+2). - _Vaclav Kotesovec_, Sep 11 2019
%t Table[Sum[2^(d + n/d), {d, Divisors[n]}], {n, 1, 30}] (* _Vaclav Kotesovec_, Sep 11 2019 *)
%o (PARI) a(n) = if(n==0,1,sumdiv(n,d, 2^d * 2^(n/d) )); \\ _Joerg Arndt_, Apr 14 2013
%Y Cf. A000079, A034733.
%K nonn
%O 1,1
%A _Erich Friedman_
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