68380

Appears in sequences

• a(n) = C(n+2, 2) + C(n+2, 3) + C(n+2, 4) + C(n+2, 5).at n=23A027660
• a(n) = n*(2*n^2 + 5*n + 19)/2.at n=40A163675
• Least integer k > 1 such that pi(k)^2 + pi(k*n)^2 is a square, where pi(.) is the prime-counting function given by A000720.at n=45A255677