Number of maximal irredundant sets in the n-ladder graph.

Terms

a(0) =2a(1) =6a(2) =9a(3) =18a(4) =54a(5) =99a(6) =216a(7) =512a(8) =1079a(9) =2352a(10) =5225a(11) =11383a(12) =24991a(13) =54814a(14) =120126a(15) =263554a(16) =577644a(17) =1266485a(18) =2777763a(19) =6089610a(20) =13352283a(21) =29278137a(22) =64194490a(23) =140755609a(24) =308628427a(25) =676706615a(26) =1483775356a(27) =3253378624a(28) =7133479611a(29) =15641147936