login
A005331
Certain subgraphs of a directed graph (binomial transform of A005321).
(Formerly M1531)
2
1, 2, 5, 20, 179, 4082, 218225, 25316720, 6135834479, 3047003143022, 3067545380897645, 6223557209578656620, 25360384878802358268779, 207167485813280961035481962, 3389045635023473628621934703465, 110960673463328354866093662279119720, 7268699514166911556909103208203294815079
OFFSET
0,2
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..81
E. Andresen and 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, and Michael J. Schlosser, Asymptotics and statistics on Fishburn Matrices: dimension distribution and a conjecture of Stoimenow, arXiv:2012.13570 [math.CO], 2020.
N. J. A. Sloane, Transforms
FORMULA
a(n) = Sum_{j=0..n} binomial(n,j)*A005321(j).
MATHEMATICA
Block[{nn = 16, s}, s = CoefficientList[Series[Sum[x^n*Product[(2^i - 1)/(1 + (2^i - 1)*x), {i, n}], {n, 0, #}], {x, 0, #}], x] &@ nn; Array[Sum[Binomial[#, j] s[[j + 1]], {j, 0, #}] &, nn + 1, 0]] (* Michael De Vlieger, Apr 13 2021, after Jean-François Alcover at A005321 *)
CROSSREFS
Sequence in context: A181076 A156871 A058109 * A261005 A158872 A308522
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Max Alekseyev, May 04 2010
a(15)-a(16) from Michael De Vlieger, Apr 13 2021
STATUS
approved