Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 01010101 or 01010111.

A260131

Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 01010101 or 01010111.

Terms

    a(0) =36a(1) =58a(2) =138a(3) =266a(4) =472a(5) =944a(6) =1880a(7) =3562a(8) =6866a(9) =13450a(10) =26016a(11) =50176a(12) =97392a(13) =188890a(14) =365434a(15) =707786a(16) =1371848a(17) =2657040a(18) =5145832a(19) =9969162a(20) =19312130a(21) =37406666a(22) =72459984a(23) =140365536a(24) =271897664a(25) =526684282a(26) =1020240874a(27) =1976299402a(28) =3828249912

External references