1456615

Appears in sequences

• a(1) = a(2) = 1; for n>2, a(n) = 4*a(n-1) + 3*a(n-2).at n=10A086901
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock having the absolute values of all six edge and diagonal differences no larger than 1.at n=28A234122