Number of ways to partition a 2*n X 2 grid into 4 connected equal-area regions.

Terms

a(0) =1a(1) =5a(2) =11a(3) =25a(4) =45a(5) =77a(6) =119a(7) =177a(8) =249a(9) =341a(10) =451a(11) =585a(12) =741a(13) =925a(14) =1135a(15) =1377a(16) =1649a(17) =1957a(18) =2299a(19) =2681a(20) =3101a(21) =3565a(22) =4071a(23) =4625a(24) =5225a(25) =5877a(26) =6579a(27) =7337a(28) =8149a(29) =9021