115435

Appears in sequences

• Number of 2 X 2 nonsingular 0..n matrices with rows in increasing order.at n=20A183761
• Number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=2A209840
• Number of (n+1)X4 0..3 arrays with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=2A209843
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order.at n=12A209848
• Expansion of Product_{k>=1} 1/(1 - psi(k)*x^k), where psi() is the Dedekind psi function (A001615).at n=16A306483