Two-rowed truncated monotone triangles.

Terms

a(0) =2a(1) =7a(2) =35a(3) =219a(4) =1594a(5) =12935a(6) =113945a(7) =1070324a(8) =10586856a(9) =109259633a(10) =1168384157a(11) =12877168147a(12) =145656436074