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 A103612 #3 Feb 27 2009 03:00:00 %S A103612 1,1,0,1,0,0,1,0,1,0,1,0,0,0,0,2,0,0,1,0,0,2,0,0,1,0,0,0,1,0,0,0,0,1, %T A103612 0,2,1,0,0,1,0,0,0,0,0,2,1,0,1,0,0,0,0,1,0,2,0,1,0,0,0,0,1,1,0,0,2,0, %U A103612 0,0,0,0,0,0,0,0,0,0,2,0,2,1,1,0,1,0,0,0,0,0,2,1,0,0,0,0,0,0,0,1,0,0,1,0,0 %N A103612 Number of solutions to 5+B^2=p^2+q^2 with B=2n, p,q>0 and 2p^2<5+B^2. %C A103612 The number of matrices with entries in Z to G^2=G+1 not of the form gI or g'I (g, the golden number and g'=1-g are the solutions to x^2=x+1), hence of the form (1+p q-B | q+B 1-p) with p^2+q^2=5+B^2 is given by 8a(n) for n!=1 and by 4a(1)=4 for n=1. %e A103612 a(0)=1 because 5+0^2=5=1^2+2^2. a(15)=2 because 5+30^2=905=8^2+29^2=11^2+28^2. %Y A103612 Cf. A104768. %K A103612 easy,nonn %O A103612 0,16 %A A103612 Michele Dondi (blazar(AT)lcm.mi.infn.it), Mar 24 2005