OFFSET
0,4
REFERENCES
F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 218.
V. A. Liskovets, A contribution to the enumeration of strongly connected digraphs, Dokl. AN BSSR, 17 (1973), 1077-1080, MR49#4849.
R. C. Read and R. J. Wilson, An Atlas of Graphs, Oxford, 1998.
R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1976.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..50 (terms 0..18 from R. W. Robinson)
A. M. Hinz, S. Klavžar, U. Milutinović, C. Petr, The Tower of Hanoi - Myths and Maths, Birkhäuser 2013. See page 251. Book's website
Eric Weisstein's World of Mathematics, Strongly Connected Digraph.
PROG
(PARI) \\ See PARI link in A350489 for program code.
A035512seq(15) \\ Andrew Howroyd, Jan 13 2022
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
Ronald C. Read
EXTENSIONS
a(12) and a(13) added by N. J. A. Sloane from the Robinson report, Oct 17 2006
STATUS
approved