35668domain: NAppears in sequencesLeast n=4 (mod 6) such that p^2 | n^n+(n+1)^(n+1) but not p | n^2+n+1, where p =A195987(k).at n=15A197319Numbers n such that n!10+1 is prime.at n=47A204656a(n) = 1 + Sum_{k=1..n-1} binomial(n-2,k-1) * a(k) * a(n-k-1).at n=9A335441