28509

Appears in sequences

• Numbers n with property that n^2 starts and ends with 81.at n=5A159775
• Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 1 vertically.at n=8A208009
• a(n) = 2*p(n)*p(n+2) - p(n+1)^2 where p(k) = k-th prime.at n=37A324795