A059735 Number of complementary pairs of tournaments on n nodes.

1, 1, 2, 3, 10, 34, 272, 3528, 97144, 4870920, 452016608, 77054901728, 24271105072736, 14200712295904928, 15510501136026729216, 31765207922047709885696, 122456389219489134370435456, 891699423142395494501906828160, 12302820585630191716774996205431296

Offset

1,3

Links

Andrew Howroyd, Table of n, a(n) for n = 1..50

Nevena Francetić, Sarada Herke, Ian M. Wanless, Parity of Sets of Mutually Orthogonal Latin Squares, arXiv:1703.04764 [math.CO], 2017. See Section 4.1.

V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.

Formula

Average of A000568 and A002785.

Mathematica

A000568 = Cases[Import["https://oeis.org/A000568/b000568.txt", "Table"], {_, _}][[All, 2]];
A002785 = Cases[Import["https://oeis.org/A002785/b002785.txt", "Table"], {_, _}][[All, 2]];
a[n_] := (A000568[[n + 1]] + A002785[[n]])/2;
Array[a, 19] (* Jean-François Alcover, Aug 27 2019 *)

Crossrefs

Cf. A000568, A002785.

Sequence in context: A057146 A344573 A300127 * A358213 A356926 A378730

Adjacent sequences: A059732 A059733 A059734 * A059736 A059737 A059738

Keyword

nonn,easy

Author

N. J. A. Sloane, Feb 09 2001

Extensions

More terms from Pab Ter (pabrlos2(AT)yahoo.com), Nov 06 2005

Terms a(18) and beyond from Andrew Howroyd, Sep 17 2018

Status

approved