201898domain: NAppears in sequencesa(n) = p^2*(p-1), where p = prime(n).at n=16A135177A002326((k-1)/2) for composite numbers k from A141229.at n=8A140198Values A such that p=prime(n) satisfies binomial(2p-1, p-1) == 1 + A*p (mod p^4).at n=16A260209