Number of 2Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.

A240761

Number of 2Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.

Terms

    a(0) =2a(1) =6a(2) =9a(3) =42a(4) =124a(5) =474a(6) =1440a(7) =5239a(8) =16730a(9) =58945a(10) =192711a(11) =666682a(12) =2209028a(13) =7562090a(14) =25254050a(15) =85922148a(16) =288250557a(17) =977287148a(18) =3287088851a(19) =11122488393a(20) =37465304475a(21) =126628657804a(22) =426895509278

External references