Number of nX4 0..1 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

A201349

Number of nX4 0..1 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

Terms

    a(0) =3a(1) =14a(2) =47a(3) =191a(4) =752a(5) =2732a(6) =9111a(7) =28011a(8) =79918a(9) =213153a(10) =535318a(11) =1274359a(12) =2892516a(13) =6291669a(14) =13172108a(15) =26642251a(16) =52229342a(17) =99517435a(18) =184747946a(19) =334871408a(20) =593751872a(21) =1031516926a(22) =1758440929a(23) =2945277335a(24) =4852655894a(25) =7873078897

External references