%I #21 Dec 24 2016 02:04:55
%S 0,1,42,569,4250,22006,88004,293369,845358,2186376,5145646,11282966,
%T 23143198,45179324,83905292,150271993,258816840,433786483,704268402,
%U 1119633944,1733618768,2640037170,3931060364,5777392406,8325691750,11873200964,16643954724,23133008124
%N a(n) = Sum_{k=1..n-1} sigma_3(k)*sigma_5(n-k).
%D J.-P. Serre, A Course in Arithmetic, Springer-Verlag, 1973, Chap. VII, Section 4.
%H Seiichi Manyama, <a href="/A279888/b279888.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = (11*sigma_9(n)-21*sigma_5(n)+10*sigma_3(n))/5040.
%t Table[Sum[If[k == 0, 0, DivisorSigma[3, k]] DivisorSigma[5, n - k], {k, 0, n - 1}], {n, 28}] (* _Michael De Vlieger_, Dec 22 2016 *)
%Y Cf. A001158, A001160, A013957, A279917.
%K nonn
%O 1,3
%A _Seiichi Manyama_, Dec 22 2016