cp's OEIS Frontend

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.

A250118 Triangle read by rows: T(n,m) (n >= 1, 1 <= m <= n) = number of set partitions of [n], avoiding 12343, with m blocks.

This page as a plain text file.
%I A250118 #28 Feb 27 2020 10:31:34
%S A250118 1,1,1,1,3,1,1,7,6,1,1,15,25,9,1,1,31,90,52,12,1,1,63,301,246,88,15,1,
%T A250118 1,127,966,1039,510,133,18,1,1,255,3025,4083,2569,909,187,21,1,1,511,
%U A250118 9330,15274,11790,5296,1470,250,24,1,1,1023,28501,55152,50644,27678,9706,2220,322,27,1
%N A250118 Triangle read by rows: T(n,m) (n >= 1, 1 <= m <= n) = number of set partitions of [n], avoiding 12343, with m blocks.
%H A250118 Lars Blomberg, <a href="/A250118/b250118.txt">Table of n, a(n) for n = 1..5050</a> (The first 100 rows.)
%H A250118 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 A250118 Triangle begins:
%e A250118   1;
%e A250118   1,    1;
%e A250118   1,    3,     1;
%e A250118   1,    7,     6,     1;
%e A250118   1,   15,    25,     9,     1;
%e A250118   1,   31,    90,    52,    12,     1;
%e A250118   1,   63,   301,   246,    88,    15,    1;
%e A250118   1,  127,   966,  1039,   510,   133,   18,    1;
%e A250118   1,  255,  3025,  4083,  2569,   909,  187,   21,   1;
%e A250118   1,  511,  9330, 15274, 11790,  5296, 1470,  250,  24,  1;
%e A250118   1, 1023, 28501, 55152, 50644, 27678, 9706, 2220, 322, 27, 1;
%e A250118   ...
%Y A250118 Cf. A112857, A250119. For diagonals see A000392, A163941.
%K A250118 nonn,tabl
%O A250118 1,5
%A A250118 _N. J. A. Sloane_, Nov 25 2014
%E A250118 a(46)-a(66) from _Lars Blomberg_, Aug 17 2017