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 A281364 #7 Feb 02 2017 02:42:09 %S A281364 21,22,55,129,511,770,1070,1071,1074,1434,1708,1914,2721,2926,3080, %T A281364 4195,4464,4814,4879,5236,5907,6086,6114,7228,7831,8029,8289,9086, %U A281364 10149,10547,11145,12305,12621,13348,14993,15012,16212,17670,19513,20020,20083 %N A281364 Numbers n such that sigma(n^3) is the sum of two positive cubes. %C A281364 265247 is the first term that is prime; sigma(265247^3) = 18661780598460480 = 48432^3 + 264708^3. In other words, the equation (1 + p)*(1 + p^2) = a^3 + b^3 where p is prime and a, b > 0, is soluble. %H A281364 Chai Wah Wu, <a href="/A281364/b281364.txt">Table of n, a(n) for n = 1..700</a> %e A281364 21 is a term because sigma(21^3) = 16000 = 20^3 + 20^3. %o A281364 (PARI) isA003325(n) = for(k=1, sqrtnint(n\2, 3), ispower(n-k^3, 3) && return(1)); %o A281364 lista(nn) = for(n=1, nn, if(isA003325(sigma(n^3)), print1(n, ", "))); %Y A281364 Cf. A000203, A000578, A003325, A175926. %K A281364 nonn %O A281364 1,1 %A A281364 _Altug Alkan_, May 01 2016