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 A084606 #7 Aug 01 2013 09:30:12
%S A084606 1,1,2,2,1,4,8,8,4,1,6,18,32,36,24,8,1,8,32,80,136,160,128,64,16,1,10,
%T A084606 50,160,360,592,720,640,400,160,32,1,12,72,280,780,1632,2624,3264,
%U A084606 3120,2240,1152,384,64,1,14,98,448,1484,3752,7448,11776,14896,15008,11872
%N A084606 Triangle, read by rows, where the n-th row lists the (2n+1) coefficients of (1+2x+2x^2)^n.
%e A084606 Rows:
%e A084606 {1},
%e A084606 {1,2,2},
%e A084606 {1,4,8,8,4},
%e A084606 {1,6,18,32,36,24,8},
%e A084606 {1,8,32,80,136,160,128,64,16},
%e A084606 {1,10,50,160,360,592,720,640,400,160,32},
%e A084606 {1,12,72,280,780,1632,2624,3264,3120,2240,1152,384,64},
%o A084606 (PARI) for(n=0,15, for(k=0,2*n,t=polcoeff((1+2*x+2*x^2)^n,k,x); print1(t",")); print(" "))
%Y A084606 Cf. A002426, A084600-A084605, A006139, A084608-A084615.
%K A084606 nonn,tabf
%O A084606 0,3
%A A084606 _Paul D. Hanna_, Jun 01 2003