T(2n+2, n), where T is the array in A055830.

Terms

a(0) =2a(1) =7a(2) =31a(3) =145a(4) =701a(5) =3458a(6) =17298a(7) =87417a(8) =445225a(9) =2281565a(10) =11750245a(11) =60763950a(12) =315315014a(13) =1641046720a(14) =8562466432a(15) =44775095601a(16) =234594444741