Number of deco polyominoes of height n and vertical height 3 (i.e., having 3 rows).

A121693

Number of deco polyominoes of height n and vertical height 3 (i.e., having 3 rows).

Terms

    a(0) =0a(1) =0a(2) =1a(3) =12a(4) =57a(5) =216a(6) =741a(7) =2412a(8) =7617a(9) =23616a(10) =72381a(11) =220212a(12) =666777a(13) =2012616a(14) =6062421a(15) =18236412a(16) =54807537a(17) =164619216a(18) =494250861a(19) =1483539012a(20) =4452189897a(21) =13359715416a(22) =40085437701a(23) =120268896012a(24) =360831853857

External references