26771

Appears in sequences

• Number of crossings in a regular drawing of the complete bipartite graph K(n,n).at n=21A159065
• Numbers n such that phi(n) = 3*phi(n+1).at n=8A256907
• Irregular triangle read by rows: T(n,k) is the number of n X n tic-tac-toe positions (up to rotation and reflection) with k tokens (i.e., after k plays) which allow a winning strategy for X (n > 0, 0 <= k <= n^2).at n=25A317573