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 A038259 #13 Jul 08 2025 22:13:58
%S A038259 1,6,5,36,60,25,216,540,450,125,1296,4320,5400,3000,625,7776,32400,
%T A038259 54000,45000,18750,3125,46656,233280,486000,540000,337500,112500,
%U A038259 15625,279936,1632960,4082400,5670000,4725000,2362500,656250,78125
%N A038259 Triangle whose (i,j)-th entry is binomial(i,j)*6^(i-j)*5^j.
%D A038259 B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.
%H A038259 Harvey P. Dale, <a href="/A038259/b038259.txt">Table of n, a(n) for n = 0..1000</a>
%e A038259 1
%e A038259 6 5
%e A038259 36 60 25
%e A038259 216 540 450 125
%e A038259 1296 4320 5400 3000 625
%e A038259 7776 32400 54000 45000 18750 3125
%t A038259 Table[Binomial[k,m]6^(k-m) 5^m,{k,0,10},{m,0,k}]//Flatten (* _Harvey P. Dale_, Aug 26 2020 *)
%Y A038259 Cf. A001020 (row sums).
%K A038259 nonn,tabl,easy
%O A038259 0,2
%A A038259 _N. J. A. Sloane_