345096domain: NAppears in sequencesCoefficient of x in the reduction by (x^2 -> x + 1) of the polynomial p(n,x) defined below at Comments.at n=12A192907Number of 5-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.at n=23A209486