54529domain: NAppears in sequencesPartial sums of A006950.at n=43A233969Semiprimes sp of the form p^2 + q + 1 where p and q are consecutive primes.at n=17A242243a(n) = Sum_{d|n} d^(n/d - d) * binomial(n/d-1,d-1).at n=27A376021