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%I #14 Feb 10 2018 21:56:01
%S 0,1,3,11,19,34,58,91,120,167,245,296,413,471,574,731,948,961,1335,
%T 1395,1645,1872,2398,2344,2994,3109,3603,3865,4865,4388,5960,5851,
%U 6608,7006,8189,7811,10203,9806,11000,11147,13930,12216,16093,15118,16459,17459
%N Sum of divisors of the products of the smaller and larger parts of the partitions of n into two parts.
%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>
%F a(n) = Sum_{i=1..floor(n/2)} sigma(i*(n-i)).
%e a(5) = 19; the partitions of 5 into two parts are (1,4) and (2,3). The sum of divisors of the products of the partitions is sigma(4) + sigma(6) = (1+2+4) + (1+2+3+6) = 7 + 12 = 19.
%p with(numtheory): A270528:=n->add(sigma(i*(n-i)), i=1..floor(n/2)): seq(A270528(n), n=1..100);
%t Table[Sum[DivisorSigma[1, i*(n - i)], {i, Floor[n/2]}], {n, 80}]
%o (PARI) a(n) = sum(i=1, n\2, sigma(i*(n-i))); \\ _Michel Marcus_, Mar 18 2016
%Y Cf. A000203, A253275.
%K nonn,easy
%O 1,3
%A _Wesley Ivan Hurt_, Mar 18 2016
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