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 A155103 #5 Jul 19 2012 05:38:56
%S A155103 1,2,1,0,0,1,6,3,0,1,0,0,0,0,1,0,0,4,0,0,1,0,0,0,0,0,0,1,30,15,0,5,0,
%T A155103 0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,6,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,
%U A155103 0,28,0,0,7,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,8,0,0,0,0,0,0
%N A155103 Triangle read by rows: Matrix inverse of A155102.
%C A155103 A028361 appears in the first column at A036987 positions. A028362 appears in the second column, A155105 in the third and A155104 in the fourth. A000384 appears as the third ray from zero and A100147 as the fourth.
%e A155103 Table begins:
%e A155103 1,
%e A155103 2,1,
%e A155103 0,0,1,
%e A155103 6,3,0,1,
%e A155103 0,0,0,0,1,
%e A155103 0,0,4,0,0,1,
%e A155103 0,0,0,0,0,0,1,
%e A155103 30,15,0,5,0,0,0,1,
%t A155103 m = 14; t = Inverse[ Table[ Which[n == k, 1, n == 2*k, -k - 1, True, 0], {n, 1, m}, {k, 1, m}]]; Flatten[ Table[t[[n, k]], {n, 1, m}, {k, 1, n}]] (* _Jean-François Alcover_, Jul 19 2012 *)
%Y A155103 Cf. A028361, A036987, A028362, A155105, A155104. A000384, A100147.
%K A155103 nonn,tabl
%O A155103 1,2
%A A155103 _Mats Granvik_, Jan 20 2009