-6359domain: ZAppears in sequencesa(n) = (1/1 - 1/(n-1) + ... + d/binomial(n-[ n/2 ],[ n/2 ]))*L, where L = LCM{1, n-1, ..., binomial(n-[ n/2 ],[ n/2 ])}, d = (-1)^n.at n=13A025580Values of n such that L(6) and N(6) are both prime, where L(k) = (n^2+n+1)*2^(2*k) + (2*n+1)*2^k + 1, N(k) = (n^2+n+1)*2^k + n.at n=31A226926