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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.
2

%I #10 Jul 11 2015 10:24:54

%S 1,1,2,6,12,72,480,864,9600,108000,312000,4795200,46293120,241056000,

%T 4759413120,94182359040,478511953920,4873965022080,122634632171520,

%U 799554193966080,23063946114908160,664424069072117760,3198456730188840960,108184656752428032000,2657146152621477888000,22850984107452933734400,863305241854715928576000,15282315334192501724774400,151673086024479840160972800

%N 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.

%C Odd analog of A086595.

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

%K nonn

%O 1,3

%A _Ray Chandler_, Jun 11 2005

%E More terms from _Max Alekseyev_, Jun 11 2005

%E a(23)-a(29) from _Max Alekseyev_, Jul 08 2014