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 A331998 #15 Feb 05 2020 10:13:20 %S A331998 1,1,3,1,13,16,1,39,171,125,1,101,1091,2551,1296,1,243,5498,28838, %T A331998 43653,16807,1,561,24270,243790,780585,850809,262144,1,1263,98661, %U A331998 1733035,10073955,22278189,18689527,4782969,1,2797,379693,10996369,106215619,410994583,677785807,457947691,100000000 %N A331998 Triangle of coefficients of quasi-Stirling polynomials. %H A331998 Sergi Elizalde, <a href="https://arxiv.org/abs/2002.00985">Descents on quasi-Stirling permutations</a>, arXiv:2002.00985 [math.CO], 2020. See p. 7. %e A331998 Triangle begins %e A331998 1; %e A331998 1, 3; %e A331998 1, 13, 16; %e A331998 1, 39, 171, 125; %e A331998 1, 101, 1091, 2551, 1296; %e A331998 1, 243, 5498, 28838, 43653, 16807; %o A331998 (PARI) %o A331998 A(t, z) = (1-t)/(1 - t*exp((1-t)*z)); %o A331998 Q(n, t) = (n!/(n+1))*polcoeff(A(t, z)^(n+1), n, z); %o A331998 row(n) = my(rowx = Vec(Q(n, t))); vector(n, k, rowx[k]); %K A331998 nonn,tabl %O A331998 1,3 %A A331998 _Michel Marcus_, Feb 05 2020