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A058157 Triangle: Labeled monoids of order n with k idempotents. 2
1, 2, 2, 3, 18, 12, 16, 180, 288, 140, 30, 2640, 6540, 8380, 3020, 480, 119610, 238200, 421020, 372360, 100362, 840, 25196052, 13786290, 26803000, 36174600, 22822674, 4768624, 22080 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..29.

Index entries for sequences related to monoids

EXAMPLE

1; 2,2; 3,18,12; 16,180,288,140; 30,2640,6540,8380,3020; ...

CROSSREFS

a(n, k)=A058158(n, k)*n. Row sums give A058153. Column 1: A034383.

Sequence in context: A049009 A101817 A058159 * A230504 A265806 A049132

Adjacent sequences:  A058154 A058155 A058156 * A058158 A058159 A058160

KEYWORD

nonn,tabl,more

AUTHOR

Christian G. Bower, Nov 14 2000

STATUS

approved

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Last modified June 19 11:24 EDT 2021. Contains 345127 sequences. (Running on oeis4.)