This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A139055 #10 Jan 07 2020 09:07:40 %S A139055 0,1,1,1,1,1,9,14,42,54,64,19,1,105,196,153,183,191,536,333,1548,1014, %T A139055 257,1649,1282,4284,3326,2870,1483,7500,4390,4419,7641,9866,7461,1, %U A139055 5435,9097,38511,50214,29913,33874,41283,22041,47954,109338,107806,77175,61579,129998 %N A139055 Sum of proper divisors of the number of partitions of n. %H A139055 Amiram Eldar, <a href="/A139055/b139055.txt">Table of n, a(n) for n = 1..10000</a> (calculated from the b-files at A000041 and A001065) %F A139055 a(n) = A001065(A000041(n)). %e A139055 a(7) = 9 because the number of partitions of 7 is 15 and the sum of proper divisors of 15 is equal to 1 + 3 + 5 = 9. %t A139055 s[n_] := DivisorSigma[1, n] - n; Array[s[PartitionsP[#]] &, 50] (* _Amiram Eldar_, Jan 07 2020 *) %o A139055 (PARI) a(n) = my(p=numbpart(n)); sigma(p) - p; \\ _Michel Marcus_, Jan 07 2020 %Y A139055 Cf. A000041, A001065, A139041. %K A139055 nonn %O A139055 1,7 %A A139055 _Omar E. Pol_, Apr 16 2008