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 A280800 #12 Jan 08 2017 12:25:29 %S A280800 0,0,0,1,0,1,0,1,0,2,0,1,0,1,0,1,0,2,0,2,1,2,0,1,1,3,1,1,0,5,0,1,2,5, %T A280800 1,2,0,4,0,2,0,4,0,2,4,2,0,1,0,4,1,3,0,5,0,1,4,4,0,5,0,1,2,1,1,6,0,5, %U A280800 2,6,0,2,0,6,1,4,1,7,0,2,2,9,0,4,4,5,0,2,0,7,1,2,1,2,1,1,0,3,1,4,0,7,0,3,3,7,0,5,0 %N A280800 a(n) = A049501(cototient(n)). %C A280800 a(n) = major index (1st definition) of cototient(n), where cototient(n) = n - phi(n). %H A280800 Indranil Ghosh, <a href="/A280800/b280800.txt">Table of n, a(n) for n = 1..10000</a> %H A280800 Indranil Ghosh, <a href="/A280800/a280800_1.txt">Python Program to generate the sequence</a> %F A280800 a(n) = A049501(A051953(n)). %e A280800 For n = 10, A051953(n) = 6 and major index (1st definition) of 6 is 2. So, a(10) = 2. %Y A280800 Cf. A049501, A051953, A280726, A280799. %K A280800 nonn %O A280800 1,10 %A A280800 _Indranil Ghosh_, Jan 08 2017