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 A202209 #6 Feb 22 2013 14:40:24
%S A202209 1,2,0,5,1,0,13,5,0,0,34,19,1,0,0,89,65,8,0,0,0,233,210,42,1,0,0,0,
%T A202209 610,654,183,11,0,0,0,0,1597,1985,717,74,1,0,0,0,0,4181,5911,2622,394,
%U A202209 14,0,0,0,0,0
%N A202209 Triangle T(n,k), read by rows, given by (2, 1/2, 1/2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 1/2, -1/2, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.
%C A202209 Riordan array ((1-x)/(1-3x+x^2), x^2/(1-3x+x^2)) .
%F A202209 T(n,k) = 3*T(n-1,k) - T(n-2,k) + T(n-2,k-1).
%F A202209 G.f.: (1-x)/(1-3x+(1-y)*x^2).
%F A202209 Sum_{k, 0<=k<=n} T(n,k)*x^k = A057682(n+1), A000079(n), A122367(n), A025192(n), A052924(n), A104934(n), A202206(n), A122117(n), A197189(n) for x = -2, -1, 0, 1, 2, 3, 4, 5, 6 respectively.
%F A202209 T(n,0) = A122367(n) = A000045(2n+1).
%e A202209 Triangle begins :
%e A202209 1
%e A202209 2, 0
%e A202209 5, 1, 0
%e A202209 13, 5, 0, 0
%e A202209 34, 19, 1, 0, 0
%e A202209 89, 65, 8, 0, 0, 0
%e A202209 233, 210, 42, 1, 0, 0, 0
%Y A202209 Cf. A000045, A000079, A001519, A001870, A001906, A126124, A202207 (antidiagonal sums)
%K A202209 nonn,tabl
%O A202209 0,2
%A A202209 _Philippe Deléham_, Dec 14 2011