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 A165253 #23 Feb 19 2020 11:33:21 %S A165253 1,1,0,1,1,0,1,3,1,0,1,6,5,1,0,1,10,15,7,1,0,1,15,35,28,9,1,0,1,21,70, %T A165253 84,45,11,1,0,1,28,126,210,165,66,13,1,0,1,36,210,462,495,286,91,15,1, %U A165253 0,1,45,330,924,1287,1001,455,120,17,1,0,1,55,495,1716,3003,3003,1820,680 %N A165253 Triangle T(n,k), read by rows given by [1,0,1,0,0,0,0,0,0,...] DELTA [0,1,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938. %C A165253 Mirror image of triangle in A121314. %H A165253 Indranil Ghosh, <a href="/A165253/b165253.txt">Rows 0..125 of triangle, flattened</a> %F A165253 T(0,0)=1, T(n,k) = binomial(n-1+k,2k) for n >= 1. %F A165253 Sum {k=0..n} T(n,k)*x^k = A000012(n), A001519(n), A001835(n), A004253(n), A001653(n), A049685(n-1), A070997(n-1), A070998(n-1), A072256(n), A078922(n), A077417(n-1), A085260(n), A001570(n) for x = 0,1,2,3,4,5,6,7,8,9,10,11,12 respectively. %F A165253 Sum_{k=0..n} T(n,k)*x^(n-k) = A000007(n), A001519(n), A047849(n), A165310(n), A165311(n), A165312(n), A165314(n), A165322(n), A165323(n), A165324(n) for x= 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 respectively. - _Philippe Deléham_, Sep 26 2009 %F A165253 T(n,k) = 2*T(n-1,k) + T(n-1,k-1) - T(n-2,k), T(0,0)=T(1,0)=1, T(1,1)=0. - _Philippe Deléham_, Feb 18 2012 %F A165253 G.f.: (1-x-y*x)/((1-x)^2-y*x). - _Philippe Deléham_, Feb 19 2012 %e A165253 Triangle begins: %e A165253 1; %e A165253 1, 0; %e A165253 1, 1, 0; %e A165253 1, 3, 1, 0; %e A165253 1, 6, 5, 1, 0; %e A165253 1, 10, 15, 7, 1, 0; %e A165253 1, 15, 35, 28, 9, 1, 0; %e A165253 1, 21, 70, 84, 45, 11, 1, 0; %e A165253 1, 28, 126, 210, 165, 66, 13, 1, 0; %e A165253 1, 36, 210, 462, 495, 286, 91, 15, 1, 0, %e A165253 1, 45, 330, 924, 1287, 1001, 455, 120, 17, 1, 0; %t A165253 m = 13; %t A165253 (* DELTA is defined in A084938 *) %t A165253 DELTA[Join[{1, 0, 1}, Table[0, {m}]], Join[{0, 1}, Table[0, {m}]], m] // Flatten (* _Jean-François Alcover_, Feb 19 2020 *) %Y A165253 Cf. A054142, A085478, A121314. %K A165253 nonn,tabl %O A165253 0,8 %A A165253 _Philippe Deléham_, Sep 10 2009