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 A129573 #6 Aug 10 2018 16:21:35 %S A129573 1,1,1,1,1,1,1,0,1,1,1,0,0,1,1,1,1,0,0,1,1,1,1,0,0,0,1,1,1,0,0,0,0,0, %T A129573 1,1,1,0,1,0,0,0,0,1,1,1,1,1,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,1,1,1,0, %U A129573 0,1,0,0,0,0,0,0,1,1,1,0,0,1,0,0,0,0,0,0,0,1,1 %N A129573 A097806 * A129372. %H A129573 Andrew Howroyd, <a href="/A129573/b129573.txt">Table of n, a(n) for n = 1..1275</a> (rows 1..50) %F A129573 A097806 * A129372 as infinite lower triangular matrices. %e A129573 First few rows of the triangle are: %e A129573 1; %e A129573 1, 1; %e A129573 1, 1, 1; %e A129573 1, 0, 1, 1; %e A129573 1, 0, 0, 1, 1; %e A129573 1, 1, 0, 0, 1, 1; %e A129573 1, 1, 0, 0, 0, 1, 1; %e A129573 1, 0, 0, 0, 0, 0, 1, 1; %e A129573 ... %o A129573 (PARI) T(n,k)=(n%k==0 && n/k%2) || ((n-1)%k==0 && (n-1)/k%2) \\ _Andrew Howroyd_, Aug 10 2018 %Y A129573 Row sums are A129574. %Y A129573 Cf. A129572, A129372, A097806. %K A129573 nonn,tabl %O A129573 1,1 %A A129573 _Gary W. Adamson_, Apr 22 2007 %E A129573 Duplicate a(35) removed and terms a(56) and beyond from _Andrew Howroyd_, Aug 10 2018