1428025domain: NAppears in sequencesk^2 is a term if k^2 + (k-1)^2 and k^2 + (k+1)^2 are primes.at n=34A075577Number of n X 6 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically.at n=14A207597Powerful numbers (A001694) whose sum of powerful divisors (including 1) is also powerful.at n=20A349109