A054932 Number of unlabeled connected digraphs up to complementarity.

1, 1, 7, 95, 4628, 760731, 439476534, 895794710762, 6512183359880844, 170617184427498641390, 16261113406024864291983616, 5683340191820651519596089554647, 7334531479545984537334675978032833750, 35157813638509073199087893774184443496308877

Offset: 1

Author

N. J. A. Sloane, May 24 2000

Keywords

• nonn
• easy

Links

• 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.

Crossrefs

Cf. A000273, A003085, A003086, A054931.

Programs

Maple

A054932 := proc(n)
    A003085(n)-(A000273(n)-A003086(n))/2 ;
end proc:
seq(A054932(n),n=1..13) ; # R. J. Mathar, Mar 04 2018

Mathematica

A000273 = Cases[Import["https://oeis.org/A000273/b000273.txt", "Table"], {, }][[All, 2]];
A003085 = Cases[Import["https://oeis.org/A003085/b003085.txt", "Table"], {, }][[All, 2]];
A003086 = Cases[Import["https://oeis.org/A003086/b003086.txt", "Table"], {, }][[All, 2]];
a[n_] := A003085[[n]] - (A000273[[n + 1]] - A003086[[n]])/2;
Array[a, 50] (* Jean-François Alcover, Sep 01 2019 *)

Formula

a(n) = A003085(n) - (A000273(n)-A003086(n))/2. - Andrew Howroyd, Sep 17 2018

Extensions

Terms a(14) and beyond from Andrew Howroyd, Sep 17 2018