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 A215589 #9 Aug 16 2012 23:23:16 %S A215589 0,1,2,0,3,1,4,2,0,5,3,1,6,4,2,7,0,5,3,8,1,6,4,9,2,7,0,5,10,3,8,1,6, %T A215589 11,4,9,2,7,12,0,5,10,3,8,13,1,6,11,4,9,14,2,7,12,0,5,10,15,3,8,13,1, %U A215589 6,11,16,4,9,14,2,7,12 %N A215589 Value of x in the n-th number of the form x+y*(1+sqrt(2)). %C A215589 A215590 gives the value of y. %H A215589 Peter G. Anderson, <a href="/A215589/b215589.txt">Table of n, a(n) for n = 1..1064</a> %Y A215589 Cf. A215590. %K A215589 nonn %O A215589 1,3 %A A215589 _Peter G. Anderson_, Aug 16 2012