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 A280306 #22 Jan 01 2017 02:35:14 %S A280306 0,0,1,2,2,4,4,13,13,16,16,28,28,46,46,46,46,77,77,48,48,48,48,117, %T A280306 117,141,141,134,134,213,213,326,326,326,326,326,326,352,352,352,352, %U A280306 389,389,413,413,413,413,508,508 %N A280306 a(n) = A049501(A003418(n)). %C A280306 This calculates the major index (1st definition) of the LCM of all the numbers from 1 to n. %H A280306 Indranil Ghosh, <a href="/A280306/b280306.txt">Table of n, a(n) for n = 0..10000</a> %H A280306 Indranil Ghosh, <a href="/A280306/a280306.txt">Python Program to generate the sequence</a> %e A280306 For n=10, the LCM of all the numbers from 1 to 10 is 2520 = 100111011000_2, whose major index (1st definition) is 16, so a(10)=16. %Y A280306 Cf. A049501, A003418, A279519. %K A280306 nonn,base %O A280306 0,4 %A A280306 _Indranil Ghosh_, Dec 31 2016