A049309 Number of nonisomorphic self-complementary circulant digraphs (Cayley digraphs for the cyclic group) of order 2n-1.

1, 1, 2, 2, 3, 4, 8, 20, 20, 30, 88, 94, 214, 457, 596, 1096, 3280, 5560, 7316, 21944, 26272, 49940

Offset

1,3

Comments

There is an easy formula for prime orders. Formulae are also known for squarefree and prime-squared orders.

Further values for squarefree and prime-squared orders can be found in the Liskovets reference.

Links

Table of n, a(n) for n=1..22.

V. A. Liskovets, Some identities for enumerators of circulant graphs, arXiv:math/0104131 [math.CO], 2001.

V. A. Liskovets and R. Poeschel, On the enumeration of circulant graphs of prime-power and squarefree orders

R. Poeschel, Publications

Crossrefs

Cf. A049288, A049289, A049297, A038785.

Sequence in context: A153922 A153943 A361117 * A239967 A307891 A205118

Adjacent sequences: A049306 A049307 A049308 * A049310 A049311 A049312

Keyword

nice,nonn

Author

Valery A. Liskovets

Extensions

a(14)-a(22) from Andrew Howroyd, May 06 2017

Status

approved