137549

Appears in sequences

• Extra strong Lucas pseudoprimes.at n=15A217719
• Smallest i such that prime(n) divides gcd(sigma(i), phi(i)) (cf. A009223).at n=31A222714
• Numbers of the form p*q, p and q prime with q=2p-3.at n=31A226755
• Number of (n+2)X(3+2) 0..1 arrays with every 3X3 subblock sum of the two medians of the central row and column plus the two sums of the diagonal and antidiagonal nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=11A259001