1415650

Appears in sequences

• From area of cyclic polygon of 2n + 1 sides.at n=9A000531
• a(n) = (n/2)*binomial(n-1, floor((n-1)/2)) - 2^(n-2).at n=20A107373
• a(n) = (-1)^n*(A056040(n+1)*A152271(n)-2^n)/2.at n=20A194590
• Row sums of A296664.at n=19A296663
• Row sums of A296662.at n=9A296769