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 A256411 #17 Mar 02 2020 08:53:45 %S A256411 1,2,8,3,37,113,4,145,1257,3492,5,452,9020,67394,183732,6,1374,60826, %T A256411 938194,6398792,17061118,7,3933,356023,30492722,466578957,3032145644, %U A256411 7743056064 %N A256411 Triangle read by rows: T(n,k) (1 <= k <= n) = number of ascendingly generated semigroups of order n with k generators. %H A256411 Alex Bailey, Martin Finn-Sell, Robert Snocken, <a href="http://arxiv.org/abs/1409.2444">Subsemigroup, ideal and congruence growth of free semigroups</a>, arXiv preprint arXiv:1409.2444 [math.GR], 2014. %e A256411 Triangle begins: %e A256411 1; %e A256411 2, 8; %e A256411 3, 37, 113; %e A256411 4, 145, 1257, 3492; %e A256411 5, 452, 9020, 67394, 183732; %e A256411 6, 1374, 60826, 938194, 6398792, 17061118; %e A256411 7, 3933, 356023, 30492722, 466578957, 3032145644, 7743056064; %e A256411 ... %Y A256411 Main diagonal is A023814. Column 2 is A256412. %K A256411 nonn,tabl,more %O A256411 1,2 %A A256411 _N. J. A. Sloane_, Apr 03 2015