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A342589
T(n,k) is the number of posets of n labeled elements with k covering relations (n>=1, k>=0). Triangle read by rows.
3
1, 1, 2, 1, 6, 12, 1, 12, 60, 128, 18, 1, 20, 180, 880, 2090, 960, 100, 1, 30, 420, 3480, 17550, 47772, 43920, 15000, 1710, 140, 1, 42, 840, 10360, 84630, 452004, 1428868, 2094960, 1465170, 491540, 90594, 10080, 770
OFFSET
1,3
EXAMPLE
The triangle starts
1: 1
2: 1 2
3: 1 6 12
4: 1 12 60 128 18
5: 1 20 180 880 2090 960 100
6: 1 30 420 3480 17550 47772 43920 15000 1710 140
7: 1 42 840 10360 84630 452004 1428868 2094960 1465170 491540 90594 10080 770
CROSSREFS
Cf. A001035 (row sums), A002378 (k=1), (A033486 (k=2?), A342447 (unlabeled), A342588 (connected).
Sequence in context: A113025 A113216 A303986 * A325635 A375753 A081064
KEYWORD
nonn,tabf
AUTHOR
R. J. Mathar, Mar 16 2021
STATUS
approved