447472972domain: NAppears in sequencesFrom area of cyclic polygon of 2n + 1 sides.at n=13A000531a(n) = (n/2)*binomial(n-1, floor((n-1)/2)) - 2^(n-2).at n=28A107373a(n) = (-1)^n*(A056040(n+1)*A152271(n)-2^n)/2.at n=28A194590Row sums of A296664.at n=27A296663Row sums of A296662.at n=13A296769