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 A280843 #7 Jan 10 2017 07:53:37 %S A280843 0,0,0,0,0,0,0,0,1,2,0,0,0,0,0,0,2,3,3,6,0,3,0,0,0,6,4,0,0,4,0,0,0,3, %T A280843 0,7,3,0,0,7,6,0,4,8,4,4,0,0,1,6,4,2,3,0,4,0,5,7,0,10,0,0,4,0,8,5,3,0, %U A280843 0,5,4,2,6,2,0,4,0,10,5,8,1,0,8,0,4,3,0,9,7,6,0,10,0,5,0,0,2,12,5,6,3,5,4,7,0,8,4,5,4 %N A280843 a(n) = A049502(sigma(n)). %C A280843 a(n) = major index (2nd definition) of the sum of the divisors of n, i.e., sigma(n). %H A280843 Indranil Ghosh, <a href="/A280843/b280843.txt">Table of n, a(n) for n = 1..10000</a> %H A280843 Indranil Ghosh, <a href="/A280843/a280843.txt">Python Program to generate the sequence</a> %F A280843 a(n) = A049502(A000203(n)). %e A280843 For n = 10, sigma(10) = 18 and major index (2nd definition) of 18 is 2. So, a(10) = 2. %Y A280843 Cf. A049501, A000203, A280799, A280815. %K A280843 nonn %O A280843 1,10 %A A280843 _Indranil Ghosh_, Jan 08 2017