A107762 - OEIS

A107762

Number of permutations of (1,3,5,7,9,...,2n-1) in which every pair of adjacent numbers as well as the first and the last entries are relatively prime.

%I #8 Jul 11 2015 10:24:41

%S 1,2,6,24,60,432,3360,6912,86400,1080000,3432000,57542400,601810560,

%T 3374784000,71391196800,1506917744640,8134703216640,87731370397440,

%U 2330058011258880,15991083879321600,484342868413071360

%N Number of permutations of (1,3,5,7,9,...,2n-1) in which every pair of adjacent numbers as well as the first and the last entries are relatively prime.

%C Odd analog of A102381. Equals n*A107763(n).

%Y Cf. A076220, A086595, A102381, A107761, A107763.

%K nonn

%O 1,2

%A _Ray Chandler_, Jun 11 2005

%E More terms from _Max Alekseyev_, Jun 11 2005