2776536

Appears in sequences

• Number of essentially different ways in which the squares 1,4,9,...,n^2 can be arranged in a sequence such that all pairs of adjacent squares sum to a prime number. Rotations and reversals are counted only once.at n=21A073451
• Number of (n+1)X(1+1) 0..3 arrays with the maximum plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=5A237922
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the maximum plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=15A237927
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the maximum plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=20A237927