31310

Appears in sequences

• Numbers n such that 203*2^n-1 is prime.at n=14A050853
• a(1) = 1; for n > 1, a(n) is the least k > a(n-1) such that a(n) + a(n-1) is square and a(n) - a(n-1) is prime.at n=28A108972
• Number of obtuse triangles, distinct up to congruence, on an n X n grid (or geoboard).at n=22A190022