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 A250119 #28 Feb 27 2020 10:11:16 %S A250119 1,1,1,1,3,1,1,7,6,1,1,15,25,10,1,1,31,90,65,14,1,1,63,301,350,121,18, %T A250119 1,1,127,966,1701,834,193,22,1,1,255,3025,7770,5037,1606,281,26,1,1, %U A250119 511,9330,34105,27918,11461,2730,385,30,1,1,1023,28501,145750,145777,73762,22381,4270,505,34,1 %N A250119 Triangle read by rows: T(n,m) (n >= 1, 1 <= m <= n) = number of set partitions of [n], avoiding 123454, with m blocks. %H A250119 Lars Blomberg, <a href="/A250119/b250119.txt">Table of n, a(n) for n = 1..5050</a> (The first 100 rows.) %H A250119 Harry Crane, <a href="https://ajc.maths.uq.edu.au/pdf/61/ajc_v61_p057.pdf">Left-right arrangements, set partitions, and pattern avoidance</a>, Australasian Journal of Combinatorics, 61(1) (2015), 57-72. %e A250119 Triangle begins: %e A250119 1; %e A250119 1, 1; %e A250119 1, 3, 1; %e A250119 1, 7, 6, 1; %e A250119 1, 15, 25, 10, 1; %e A250119 1, 31, 90, 65, 14, 1; %e A250119 1, 63, 301, 350, 121, 18, 1; %e A250119 1, 127, 966, 1701, 834, 193, 22, 1; %e A250119 1, 255, 3025, 7770, 5037, 1606, 281, 26, 1; %e A250119 1, 511, 9330, 34105, 27918, 11461, 2730, 385, 30, 1; %e A250119 1, 1023, 28501, 145750, 145777, 73762, 22381, 4270, 505, 34, 1; %e A250119 ... %Y A250119 Cf. A112857, A250118. A163942 is a diagonal. %K A250119 nonn,tabl %O A250119 1,5 %A A250119 _N. J. A. Sloane_, Nov 25 2014 %E A250119 a(46)-a(66) from _Lars Blomberg_, Aug 17 2017