A049387 -id:A049387 - cp's OEIS frontend

A035512 Number of unlabeled strongly connected digraphs with n nodes.

1, 1, 1, 5, 83, 5048, 1047008, 705422362, 1580348371788, 12139024825260556, 328160951349343885604, 31831080872412589394328804, 11234274997368899732057135454531, 14576252633139820879894296847900227082

Offset: 0

Ronald C. Read

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.

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.

The labeled version is A003030.
Row sums of A057276.
Column sums of A350753.
Cf. A003085, A049387, A350489, A350752.

\\ See PARI link in A350489 for program code.
A035512seq(15) \\ Andrew Howroyd, Jan 13 2022

a(12) and a(13) added by N. J. A. Sloane from the Robinson report, Oct 17 2006

A054951 Number of unlabeled semi-strong digraphs on n nodes with mutually nonisomorphic components.

Original entry on oeis.org

1, 1, 4, 78, 4960, 1041872, 704369984, 1579641879248, 12137443766888448, 328148810741254606592, 31830752699315833628787200, 11234243165959817684710307801600, 14576241398832991116522929933694031872, 70075699209573863790264288901653500497274880

Offset: 1

N. J. A. Sloane, May 24 2000

A digraph is semi-strong if all its weakly connected components are strongly connected. - Andrew Howroyd, Jan 14 2022

V. A. Liskovets, A contribution to the enumeration of strongly connected digraphs, Dokl. AN BSSR, 17 (1973), 1077-1080 (Russian), MR49#4849.

Andrew Howroyd, Table of n, a(n) for n = 1..50
V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.

Cf. A035512, A049387, A054952, A054953, A054954.

m = 15;
A035512 = Cases[Import["https://oeis.org/A035512/b035512.txt", "Table"], {, }][[All, 2]];
gf = 1 - Product[(1 - x^n)^A035512[[n + 1]], {n, 1, m}];
CoefficientList[gf + O[x]^m , x] // Rest (* Jean-François Alcover, Aug 26 2019, after Andrew Howroyd *)

G.f.: 1 - Product_{n > 0} (1 - x^n)^A035512(n). - Andrew Howroyd, Sep 10 2018

More terms from Vladeta Jovovic, Mar 11 2003

a(12)-a(14) from Andrew Howroyd, Sep 10 2018

cp's OEIS Frontend

A035512 Number of unlabeled strongly connected digraphs with n nodes.

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