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 A244578 #15 Mar 22 2024 04:22:28 %S A244578 1,2,6,13,33,50,85,107,155,255,298,433,523,578,678,873,1076,1185,1421, %T A244578 1581,1705,1968,2159,2494,3002,3250,3365,3615,3788,4072,5152,5449, %U A244578 5990,6141,7057,7280,7917,8507,8847,9553,10164,10531,11646,11963,12408,12679 %N A244578 Sum of all aliquot divisors of all positive integers <= prime(n). %F A244578 a(n) = A153485(A000040(n)). %F A244578 a(n) ~ (Pi^2/12 - 1/2) * n^2 * log(n)^2. - _Amiram Eldar_, Mar 22 2024 %o A244578 (PARI) a(n) = sum(i=1, prime(n), sigma(i)-i); \\ _Michel Marcus_, Sep 29 2014 %Y A244578 Cf. A000040, A000203, A001065, A153485, A244576, A244583. %K A244578 nonn %O A244578 1,2 %A A244578 _Omar E. Pol_, Jun 30 2014 %E A244578 More terms from _Michel Marcus_, Sep 29 2014