6624720

Appears in sequences

• Number of 2 X n 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero.at n=10A230470
• Triangle T(n,k) read by rows: connected topologies of Goldstone diagrams with n interactions and k external potentials.at n=21A328923