Number of no-leaf subgraphs of the 2 X n grid up to horizontal and vertical reflection.

A303930

Number of no-leaf subgraphs of the 2 X n grid up to horizontal and vertical reflection.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =10a(4) =26a(5) =76a(6) =232a(7) =750a(8) =2493a(9) =8514a(10) =29524a(11) =103708a(12) =367225a(13) =1308542a(14) =4682276a(15) =16807286a(16) =60462082a(17) =217855460a(18) =785863048a(19) =2837177434a(20) =10249053629a(21) =37039804078a(22) =133902392980a(23) =484178868612

External references