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 A127831 #2 Mar 30 2012 18:59:19 %S A127831 1,0,1,0,0,1,0,0,-1,1,0,0,1,-1,1,0,0,0,0,0,1,0,0,-1,1,-1,0,1,0,0,1,-1, %T A127831 1,-1,-1,1,0,0,0,0,0,1,0,-1,1,0,0,0,0,0,1,0,-1,0,1,0,0,-1,1,-1,1,1,-1, %U A127831 0,0,1 %N A127831 Inverse of number triangle mod(C(floor(k/2),n-k),2). %C A127831 Row sums are A085357. Inverse of A127829. %e A127831 Triangle begins %e A127831 1, %e A127831 0, 1, %e A127831 0, 0, 1, %e A127831 0, 0, -1, 1, %e A127831 0, 0, 1, -1, 1, %e A127831 0, 0, 0, 0, 0, 1, %e A127831 0, 0, -1, 1, -1, 0, 1, %e A127831 0, 0, 1, -1, 1, -1, -1, 1, %e A127831 0, 0, 0, 0, 0, 1, 0, -1, 1, %e A127831 0, 0, 0, 0, 0, 1, 0, -1, 0, 1, %e A127831 0, 0, -1, 1, -1, 1, 1, -1, 0, 0, 1 %K A127831 sign,tabl %O A127831 0,1 %A A127831 _Paul Barry_, Feb 01 2007