A054929 Number of complementary pairs of circulant graphs on n nodes.

1, 1, 1, 2, 2, 4, 2, 6, 4, 10, 4, 24, 8, 24, 22, 42, 20, 96, 30, 168, 100, 208, 94, 656, 215, 700, 464, 1552, 596, 4384, 1096, 4182, 3384, 8230, 5572, 23392, 7316, 29144, 22212, 68064, 26272, 177600, 49940, 216288, 175712, 381304, 182362, 1061472, 399476

Offset: 1

Author

N. J. A. Sloane, May 24 2000

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..64
• V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.

Crossrefs

Cf. A049287, A049289, A054930.

Formula

Average of A049287 and A049289.

a(n) = A049287(n)/2 for n mod 4 <> 1; a(n) = (A049287(n) + A049289((n-1)/4))/2 for n mod 4 = 1. - Andrew Howroyd, Jan 16 2022

Extensions

Terms a(19) and beyond from Andrew Howroyd, Jan 16 2022