A259970 Triangle read by rows: coefficients eta(n,k) arising from the study of completely transitive graphs on n nodes.

1, 0, 1, 1, 3, 3, 6, 28, 42, 21, 91, 510, 1050, 945, 315, 2820, 18631, 48360, 61845, 39060, 9765, 177661, 1351413, 4220433, 6942915, 6357015, 3075975, 615195

Offset

1,5

Links

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

E. Andresen, K. Kjeldsen, On certain subgraphs of a complete transitively directed graph, Discrete Math. 14 (1976), no. 2, 103-119.

Hsien-Kuei Hwang, Emma Yu Jin, Michael J. Schlosser, Asymptotics and statistics on Fishburn Matrices: dimension distribution and a conjecture of Stoimenow, arXiv:2012.13570 [math.CO], Dec 25 2020, p. 29.

Example

Triangle begins:
1,
0,1,
1,3,3,
6,28,42,21,
91,510,1050,945,315,
2820,18631,48360,61845,39060,9765,
177661,1351413,4220433,6942915,6357015,3075975,615195,
...

Crossrefs

Cf. A259971, A259972.

Diagonals include A005327, A005328, A005329.

Row sums are A005014.

Sequence in context: A019235 A222020 A230253 * A221824 A221898 A103895

Adjacent sequences: A259967 A259968 A259969 * A259971 A259972 A259973

Keyword

nonn,more,tabl

Author

N. J. A. Sloane, Jul 11 2015

Status

approved