84377domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that 157*2^k-1 is prime.at n=21A050830Primes from merging of 5 successive digits in decimal expansion of Zeta(2) or (Pi^2)/6.at n=6A105378Number of unlabeled rooted trees with 2n nodes and maximal outdegree (branching factor) n.at n=11A244407Prime numbersat n=8223