350090

Appears in sequences

• Numbers k such that k^2 + k - 1 and k^2 + k + 1 are twin primes and (k + 1)*(k + 1) + k + 1 - 1 and (k + 1)*(k + 1) + k + 1 + 1 are also twin primes.at n=32A088498
• a(n) = a(n-1) - (n-1)*a(n-4), with a(0) = 0, a(1) = 1, a(2) = 2, a(3) = 1.at n=20A122022
• Number of planar rooted Eulerian orientations (i.e., planar directed Eulerian maps with in-degree and out-degree equal for each vertex) with n edges.at n=7A277493