Number of possible 3 X n arrangements of black and white squares that can form the middle three rows in an n X n crossword puzzle with rotational symmetry. In this sequence, n is ODD.
A133258
Number of possible 3 X n arrangements of black and white squares that can form the middle three rows in an n X n crossword puzzle with rotational symmetry. In this sequence, n is ODD.
Terms
- a(0) =1a(1) =11a(2) =38a(3) =157a(4) =718a(5) =3039a(6) =12571
External references
- oeis: A133258