T(n,k)=1/4 the number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.

A209553

T(n,k)=1/4 the number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.

Terms

    a(0) =7a(1) =20a(2) =20a(3) =61a(4) =105a(5) =61a(6) =191a(7) =562a(8) =562a(9) =191a(10) =603a(11) =3051a(12) =5075a(13) =3051a(14) =603a(15) =1909a(16) =16582a(17) =46515a(18) =46515a(19) =16582a(20) =1909a(21) =6049a(22) =90186a(23) =425803a(24) =723636a(25) =425803a(26) =90186a(27) =6049a(28) =19173a(29) =490547

External references