Integers k such that k-1,k,k+1 have few distinct primes: k=p^r, p odd prime, and (k^2-1)/8 divisible by at most two distinct prime factors.

A172095

Integers k such that k-1,k,k+1 have few distinct primes: k=p^r, p odd prime, and (k^2-1)/8 divisible by at most two distinct prime factors.