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 A236376 #15 Mar 06 2022 12:05:28
%S A236376 1,1,1,2,3,1,3,7,5,1,4,14,16,7,1,5,25,41,29,9,1,6,41,91,92,46,11,1,7,
%T A236376 63,182,246,175,67,13,1,8,92,336,582,550,298,92,15,1,9,129,582,1254,
%U A236376 1507,1079,469,121,17,1,10,175,957,2508,3718,3367,1925,696,154
%N A236376 Riordan array ((1-x+x^2)/(1-x)^2, x/(1-x)^2).
%C A236376 Triangle T(n,k), read by rows, given by (1, 1, -1, 1, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.
%C A236376 Row sums are A111282(n+1) = A025169(n-1).
%C A236376 Diagonal sums are A122391(n+1) = A003945(n-1).
%F A236376 G.f.: (1 - x + x^2)/(1 - 2*x - x*y + x^2).
%F A236376 T(n,k) = 2*T(n-1,k) + T(n-1,k-1) - T(n-2,k), T(0,0) = T(1,0) = T(1,1) = 1, T(2,0) = 2, T(2,1) = 3, T(2,2) = 1, T(n,k) = 0 if k < 0 or k > n.
%F A236376 The Riordan square (see A321620) of 1 + x/(1 - x)^2. - _Peter Luschny_, Mar 06 2022
%e A236376 Triangle begins:
%e A236376 1;
%e A236376 1, 1;
%e A236376 2, 3, 1;
%e A236376 3, 7, 5, 1;
%e A236376 4, 14, 16, 7, 1;
%e A236376 5, 25, 41, 29, 9, 1;
%e A236376 6, 41, 91, 92, 46, 11, 1;
%e A236376 7, 63, 182, 246, 175, 67, 13, 1;
%p A236376 # The function RiordanSquare is defined in A321620.
%p A236376 RiordanSquare(1+x/(1-x)^2, 8); # _Peter Luschny_, Mar 06 2022
%t A236376 CoefficientList[#, y] & /@
%t A236376 CoefficientList[
%t A236376 Series[(1 - x + x^2)/(1 - 2*x - x*y + x^2), {x, 0, 12}], x] (* _Wouter Meeussen_, Jan 25 2014 *)
%Y A236376 Cf. Columns: A028310, A004006.
%Y A236376 Cf. Diagonals: A000012, A005408, A130883.
%Y A236376 Cf. Similar sequences: A078812, A085478, A111125, A128908, A165253, A207606.
%Y A236376 Cf. A321620.
%K A236376 nonn,tabl
%O A236376 0,4
%A A236376 _Philippe Deléham_, Jan 24 2014