66401domain: NAppears in sequencessech(arctan(arcsinh(x)))=1-1/2!*x^2+17/4!*x^4-769/6!*x^6+66401/8!*x^8...at n=4A012221a(1) = 1; for n>1, a(n) = the smallest number p > a(n-1) such that (a(n-1)+p)/2 is a cube.at n=39A126950Number of aperiodic necklaces (Lyndon words) with k<=6 black beads and n-k white beads.at n=36A277631