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 A038335 #11 Jul 08 2025 22:22:08
%S A038335 1,12,9,144,216,81,1728,3888,2916,729,20736,62208,69984,34992,6561,
%T A038335 248832,933120,1399680,1049760,393660,59049,2985984,13436928,25194240,
%U A038335 25194240,14171760,4251528,531441,35831808,188116992,423263232
%N A038335 Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*9^j.
%D A038335 B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.
%e A038335 1
%e A038335 12 9
%e A038335 144 216 81
%e A038335 1728 3888 2916 729
%e A038335 20736 62208 69984 34992 6561
%e A038335 248832 933120 1399680 1049760 393660 59049
%e A038335 2985984 13436928 25194240 25194240 14171760 4251528 531441
%p A038335 A038335 := proc(i,j)
%p A038335 binomial(i,j)*12^(i-j)*9^j ;
%p A038335 end proc: # _R. J. Mathar_, Nov 22 2022
%t A038335 Flatten[Table[Binomial[i,j]12^(i-j) 9^j,{i,0,10},{j,0,i}]] (* _Harvey P. Dale_, Oct 17 2013 *)
%Y A038335 Cf. A009965 (row sums), A001021 (column 0), A001019 (diagonal)
%K A038335 nonn,tabl,easy
%O A038335 0,2
%A A038335 _N. J. A. Sloane_