220221domain: NAppears in sequencesNumber of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-2.at n=35A211958Smallest positive integer m such that (m^(2^n) + 1)/2 is prime.at n=15A275530