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A250118 Triangle read by rows: T(n,m) (n >= 1, 1 <= m <= n) = number of set partitions of [n], avoiding 12343, with m blocks. 3
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, 1, 127, 966, 1039, 510, 133, 18, 1, 1, 255, 3025, 4083, 2569, 909, 187, 21, 1, 1, 511, 9330, 15274, 11790, 5296, 1470, 250, 24, 1, 1, 1023, 28501, 55152, 50644, 27678, 9706, 2220, 322, 27, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Lars Blomberg, Table of n, a(n) for n = 1..5050 (The first 100 rows.)

Harry Crane, Left-right arrangements, set partitions, and pattern avoidance, Australasian Journal of Combinatorics, 61(1) (2015), 57-72.

EXAMPLE

Triangle begins:

  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;

  1,  127,   966,  1039,   510,   133,   18,    1;

  1,  255,  3025,  4083,  2569,   909,  187,   21,   1;

  1,  511,  9330, 15274, 11790,  5296, 1470,  250,  24,  1;

  1, 1023, 28501, 55152, 50644, 27678, 9706, 2220, 322, 27, 1;

  ...

CROSSREFS

Cf. A112857, A250119. For diagonals see A000392, A163941.

Sequence in context: A154341 A202181 A130749 * A250119 A154959 A080417

Adjacent sequences:  A250115 A250116 A250117 * A250119 A250120 A250121

KEYWORD

nonn,tabl

AUTHOR

N. J. A. Sloane, Nov 25 2014

EXTENSIONS

a(46)-a(66) from Lars Blomberg, Aug 17 2017

STATUS

approved

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Last modified February 24 06:13 EST 2018. Contains 299597 sequences. (Running on oeis4.)