1,3
There is an easy formula for prime orders. Formulae are also known for squarefree and prime-squared orders. The subsequent values for orders 29,31 are 596,1096.
V. A. Liskovets, Some identities for enumerators of circulant graphs.
V. A. Liskovets and R. Poeschel, On the enumeration of circulant graphs of prime-power and squarefree orders
R. Poeschel, Publications
Cf. A049288, A049289, A049297.
Sequence in context: A032243 A153922 A153943 * A205118 A022405 A093927
Adjacent sequences: A049306 A049307 A049308 * A049310 A049311 A049312
nice,nonn
V. A. Liskovets (liskov(AT)im.bas-net.by)
Further values for (twice) squarefree and (twice) prime-squared orders can be found in the Liskovets reference.
