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 A067402 #21 Sep 30 2022 09:57:05
%S A067402 1,1,1,1,3,1,1,12,5,1,1,48,45,7,1,1,192,405,112,9,1,1,768,3645,1792,
%T A067402 225,11,1,1,3072,32805,28672,5625,396,13,1,1,12288,295245,458752,
%U A067402 140625,14256,637,15,1,1,49152,2657205,7340032,3515625,513216,31213,960,17,1
%N A067402 Triangle with columns built from certain power sequences.
%H A067402 Indranil Ghosh, <a href="/A067402/b067402.txt">Rows 0..125, flattened</a>
%F A067402 a(n, m) = 1 if n=m; a(n, m) = (2*m+1)*(m+1)^(2*(n-m-1)) if n>m>=0.
%F A067402 G.f. for column m: (x^m)*(1-x*m^2)/(1-x*(m+1)^2).
%e A067402 Triangle starts:
%e A067402 m=0 1 2 3 4
%e A067402 n=0: 1;
%e A067402 n=1: 1, 1;
%e A067402 n=2: 1, 3, 1;
%e A067402 n=3: 1, 12, 5, 1;
%e A067402 n=4: 1, 48, 45, 7, 1;
%e A067402 ...
%t A067402 A[n_,m_]:=If[n==m,1,(2m+1)(m+1)^(2(n-m-1))]; Flatten[Table[A[n,m],{n,0,9},{m,0,n}]] (* _Stefano Spezia_, Sep 30 2022 *)
%Y A067402 Cf. A009998 (triangle built from powers of (m+1)).
%Y A067402 Columns m=0..8: A000012, A002001, A067403-A067409.
%K A067402 nonn,easy,tabl
%O A067402 0,5
%A A067402 _Wolfdieter Lang_, Jan 25 2002
%E A067402 More terms from Larry Reeves (larryr(AT)acm.org), Jun 11 2002