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 A168216 #3 Sep 08 2013 13:31:50
%S A168216 1,1,1,1,3,1,1,8,5,1,1,23,19,7,1,1,74,69,34,9,1,1,262,256,147,53,11,1,
%T A168216 1,993,986,615,265,76,13,1,1,3943,3935,2571,1235,431,103,15,1,1,16178,
%U A168216 16169,10862,5591,2216,653,134,17,1
%N A168216 Riordan array (1/(1-x),xc(x)/(1-xc(x))) where c(x)is the g.f. of A000108.It factorizes as A007318*A106566.
%C A168216 Inverse is Riordan array (1/(1+x-x^2),x(1-x)/(1+x-x^2)) = [ -1,-1,1,0,0,0,0,0,...]DELTA[1,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938. Unsigned version of A091698.
%F A168216 Sum_{k, 0<=k<=n}T(n,k)*x^k = A000012(n), A007317(n+1), A026375(n) for x = 0, 1, 2 respectively.
%e A168216 Triangle begins : 1 ; 1,1 ; 1,3,1 ; 1,8,5,1 ; 1,23,19,7,1 ; ...
%Y A168216 Cf. A000108, A007318, A106566.
%K A168216 nonn,tabl
%O A168216 0,5
%A A168216 _Philippe Deléham_, Nov 20 2009