312130domain: NAppears in sequencesa(n) = (a(n-1) - a(n-3))*7^((1+(-1)^n)/2) with a(6)=5, a(7)=4, a(8)=22.at n=16A215139a(n) = cpg(n, 3) + cpg(n, 4) + ... + cpg(n, n) where cpg(n, m) is the m-th n-th-order centered polygonal number.at n=37A257051