65681domain: NAppears in sequencestanh(arcsin(tanh(x)))=x-3/3!*x^3+41/5!*x^5-1243/7!*x^7+65681/9!*x^9...at n=4A012129Gaps of 2 in sequence A038593 (lower terms).at n=30A038643a(n) = n^3 + (n+1)^2.at n=40A100705Second-order spt function.at n=21A221140