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 A070304 #5 Mar 30 2012 18:38:58 %S A070304 1,2,1,2,2,2,1,2,1,6,1,2,1,2,3,2,2,2,1,7,1,2,1,2,2,4,1,2,1,8,1,2,1,3, %T A070304 2,2,2,2,2,7,1,2,1,2,3,2,1,2,1,7,2,4,1,2,2,2,1,4,1,9,1,2,1,2,5,2,1,4, %U A070304 1,7,1,2,1,3,3,2,1,5,1,7,1,3,1,2,4,2,1,2,1,8,1,2,1,2,2,2,1,2,1,8,2,4,1,4,3 %N A070304 a(n) = number of times n^2*k^2/(n^2+k^2) is an integer as k ranges over 0, 1, 2, ... %C A070304 A018892(n) gives the number of integers of the form nk/(n+k). %o A070304 (PARI) for(n=1,150,print1(sum(i=0,n^2,if((n^2*i^2)%(n^2+i^2),0,1)),",")) %Y A070304 Cf. A066451. %K A070304 easy,nonn %O A070304 1,2 %A A070304 _Benoit Cloitre_, May 10 2002