Number of nX3 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.

A301657

Number of nX3 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.

Terms

    a(0) =3a(1) =4a(2) =6a(3) =9a(4) =15a(5) =26a(6) =46a(7) =83a(8) =151a(9) =276a(10) =506a(11) =929a(12) =1707a(13) =3138a(14) =5770a(15) =10611a(16) =19515a(17) =35892a(18) =66014a(19) =121417a(20) =223319a(21) =410746a(22) =755478a(23) =1389539a(24) =2555759a(25) =4700772a(26) =8646066a(27) =15902593a(28) =29249427a(29) =53798082

External references