%I #6 Aug 06 2024 02:08:24
%S 1,5,14,46,71,287,336,848,1091,2091,2212,22948,23117,25861,29236,
%T 45620,45909,150885,151246,311246,320507,331155,331684,8294308,
%U 8297433,8315009,8334692,8949348,8950189,33250189,33251150,34299726,34335663,34374967,34417842,397214898
%N a(n) = Sum_{k<=n} A007955(k) * A000027(k) = Sum_{k<=n} A007955(k) * k, where A007955(m) = product of divisors of m.
%e For n = 4, A007955(n) = b(n): a(4) = b(1)*1 + b(2)*2 + b(3)* 3 + b(4)*4 = 1*1 + 2*2 + 3*3 + 8*4 = 46.
%t a[n_] := Sum[k^(DivisorSigma[0, k]/2 + 1), {k, 1, n}]; Array[a, 50] (* _Amiram Eldar_, Aug 06 2024 *)
%Y Cf. A000027, A007955.
%K nonn
%O 1,2
%A _Jaroslav Krizek_, Apr 02 2010
%E More terms from _Amiram Eldar_, Aug 06 2024