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 A090174 #8 Apr 20 2015 04:22:47 %S A090174 1,1,1,0,1,0,1,1,1,1,1,1,1,1,1,0,0,1,1,0,0,1,0,0,1,0,0,1,1,1,1,1,1,1, %T A090174 1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,0,1,1,0,0, %U A090174 0,0,1,1,1,1,0,0,0,0,1,0,0,0,1,1,1,1,1,0,0,0,1,1,1,0,0,0,0,1,1,0,0,0,0,1,1 %N A090174 Triangle read by rows, related to Pascal's triangle read mod 2. %H A090174 Y. Moshe, <a href="http://dx.doi.org/10.1016/S0022-314X(03)00103-3">The density of 0's in recurrence double sequences</a>, J. Number Theory, 103 (2003), 109-121; see Fig. 2. %F A090174 a(n, k) = A091533(n, k) mod 2. %e A090174 1; 1,1; 0,1,0; 1,1,1,1; 1,1,1,1,1; ... %Y A090174 Row sums: A091564. Cf. A007318, A083093, A090171-A090173. %K A090174 nonn,easy,tabl %O A090174 0,1 %A A090174 _N. J. A. Sloane_, Jan 19 2004 %E A090174 Edited and extended by _Christian G. Bower_, Jan 19 2004