21668208

Appears in sequences

• Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.at n=4A220546
• Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.at n=4A220550
• T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor.at n=40A220553