a(n)=T(n,n+2), array T as in A049600.

Terms

a(0) =0a(1) =1a(2) =6a(3) =34a(4) =190a(5) =1059a(6) =5908a(7) =33028a(8) =185076a(9) =1039525a(10) =5851626a(11) =33006438a(12) =186519138a(13) =1055789511a(14) =5985405000a(15) =33979107336a(16) =193143097288