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A058113 Triangle: Number of asymmetric semigroups of order n with k idempotents. 3
1, 2, 1, 3, 9, 3, 11, 37, 52, 12, 112, 224, 434, 383, 68, 4398, 1984, 3976, 5568, 3256, 502, 1181185, 47622, 44581, 74851, 74604, 31881, 4158 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..28.

Index entries for sequences related to semigroups

EXAMPLE

1; 2,1; 3,9,3; 11,37,52,12; 112,224,434,383,68; ...

CROSSREFS

Row sums give A058104. Main diagonal: A058115. Column 1: A058114.

Sequence in context: A083782 A076240 A099644 * A249456 A234746 A237765

Adjacent sequences:  A058110 A058111 A058112 * A058114 A058115 A058116

KEYWORD

nonn,tabl,hard

AUTHOR

Christian G. Bower, Nov 09 2000

EXTENSIONS

Updated Feb 19 2001

STATUS

approved

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Last modified October 20 15:44 EDT 2018. Contains 316389 sequences. (Running on oeis4.)