%I #10 Mar 26 2019 09:04:28
%S 2,14,46,158,350,1118,2142,5982,12638,31070,55646,170334,285022,
%T 678238,1464670,3496286,5855582,16079198,26564958,70605150,137714014,
%U 288708958,490035550,1496668510,2536855902,5355428190,10724137310,25756522846,41862650206,119172061534
%N a(n) = Sum_{k=1..n} 2^k * sigma(k), where sigma(k) = A000203(k).
%H Vaclav Kotesovec, <a href="/A324915/a324915.jpg">Plot of a(n)/(n*2^n) for n = 1..100000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DivisorFunction.html">Divisor Function</a>
%t Accumulate[Table[2^k*DivisorSigma[1, k], {k, 1, 30}]]
%Y Cf. A000203, A024916, A185003, A324914.
%K nonn
%O 1,1
%A _Vaclav Kotesovec_, Mar 18 2019
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