Number of n X 1 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

A201618

Number of n X 1 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

Terms

    a(0) =0a(1) =4a(2) =4a(3) =10a(4) =16a(5) =26a(6) =40a(7) =59a(8) =84a(9) =116a(10) =156a(11) =205a(12) =264a(13) =334a(14) =416a(15) =511a(16) =620a(17) =744a(18) =884a(19) =1041a(20) =1216a(21) =1410a(22) =1624a(23) =1859a(24) =2116a(25) =2396a(26) =2700a(27) =3029a(28) =3384a(29) =3766

External references