20493

Appears in sequences

• Number of nondividing sets on {1,2,...,n}.at n=39A051014
• Numbers n such that n | 12^n + 11^n + 10^n + 9^n + 8^n + 7^n.at n=34A057257
• Number of inequivalent (ordered) solutions to n^2 = sum of 8 squares of integers >= 0.at n=40A065462
• Smallest odd number k such that p(2m)-2p(m)=k has exactly n solutions (where p(m) = m-th prime).at n=13A069890
• Non-palindromic numbers n such that phi(n) = phi(reversal(n)).at n=18A097647
• a(n) = n*(n+1)*(11*n+1)/6.at n=22A132112
• Number of (n+1)X(7+1) 0..1 arrays with every 2X2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically.at n=13A253396