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 A122760 #7 Mar 12 2014 16:36:58
%S A122760 0,2,6,0,0,0,2,6,18,54,0,0,0,0,0,2,6,18,54,162,486,0,0,0,0,0,0,0,2,6,
%T A122760 18,54,162,486,1458,4374,0,0,0,0,0,0,0,0,0,2,6,18,54,162,486,1458,
%U A122760 4374,13122,39366,0,0,0,0,0,0,0,0,0,0,0
%N A122760 Triangle read by rows: t(n,m) = 2*3^m*(n mod 2).
%C A122760 A Cantor-based power of 3 triangular array.
%D A122760 Lynn Arthur Steen and J. Arthur Seebach, Jr., Counterexamples in Topology, Dover, New York, 1978, 57-58
%e A122760 0
%e A122760 2, 6
%e A122760 0, 0, 0
%e A122760 2, 6, 18, 54
%e A122760 0, 0, 0, 0, 0
%e A122760 2, 6, 18, 54, 162, 486
%e A122760 0, 0, 0, 0, 0, 0, 0
%e A122760 2, 6, 18, 54, 162, 486, 1458, 4374
%t A122760 b[n_] := 2*Mod[n, 2] T2[n_, m_] := 3^n*b[m] b0 = Table[Table[T2[n, m], {n, 0, m}], {m, 0, 10}]; Flatten[b0] MatrixForm[b0]
%Y A122760 Row sums: see A024101.
%K A122760 nonn,tabl
%O A122760 1,2
%A A122760 _Roger L. Bagula_, Sep 21 2006
%E A122760 Edited and corrected by _N. J. A. Sloane_, May 29 2009