A107763 Number of ways to arrange the numbers (1,3,5,7,9,...,2n-1) in a circle such that every two adjacent numbers are relatively prime.

1, 1, 2, 6, 12, 72, 480, 864, 9600, 108000, 312000, 4795200, 46293120, 241056000, 4759413120, 94182359040, 478511953920, 4873965022080, 122634632171520, 799554193966080, 23063946114908160, 664424069072117760, 3198456730188840960, 108184656752428032000, 2657146152621477888000, 22850984107452933734400, 863305241854715928576000, 15282315334192501724774400, 151673086024479840160972800

Offset

1,3

Comments

Odd analog of A086595.

Links

Table of n, a(n) for n=1..29.

Crossrefs

Cf. A076220, A086595, A102381, A107761, A107762.

Sequence in context: A258213 A178846 A173843 * A166470 A144144 A226178

Adjacent sequences: A107760 A107761 A107762 * A107764 A107765 A107766

Keyword

nonn

Author

Ray Chandler, Jun 11 2005

Extensions

More terms from Max Alekseyev, Jun 11 2005

a(23)-a(29) from Max Alekseyev, Jul 08 2014

Status

approved