151946

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 31.at n=20A031619
• Duplicate of A099760.at n=7A099758
• a(n+1) = 2*n*a(n) + 2 with a(0)=1.at n=7A099760
• Number of (3+1) X (n+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=7A253497