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 A147795 #8 Sep 08 2013 19:59:24 %S A147795 0,0,1,1,2,2,3,3,6,6,7,7,8,8,9,9,12,12,13,13,14,14,15,15,18,18,19,19, %T A147795 20,20,21,21,28,28,29,29,30,30,31,31,34,34,35,35,36,36,37,37,40,40,41, %U A147795 41,42,42,43,43,46,46,47,47,48,48,49,49 %N A147795 If n=A000695(k_n)+2*A000695(l_n), then a(n) is the number of nonnegative integers m<n such that k_m differs from k_n and l_m differs from l_n. %C A147795 Let us call integers m and n collinear one to another if either A059905(m)=A059905(n) or A059906(m)=A059906(n). Then a(n) is the number of noncollinear to n nonnegative integers not exceeding n. %F A147795 Theorem: a(2n)=a(2n+1). %Y A147795 Cf. A000695, A054238, A059905, A059906. %K A147795 nonn %O A147795 0,5 %A A147795 _Vladimir Shevelev_, Nov 13 2008 %E A147795 More terms from _Philippe Deléham_, Oct 18 2011