a(2)=1, a(3)=2; thereafter a(n) = 2a(n-1)-a(n-2)+A046919(n).

Terms

a(0) =1a(1) =2a(2) =4a(3) =9a(4) =22a(5) =59a(6) =169a(7) =506a(8) =1577a(9) =5078a(10) =16729a(11) =56098a(12) =190981a(13) =658442a(14) =2294164a(15) =8066363a(16) =28588554a(17) =102036631a(18) =366458118a(19) =1323463507a(20) =4803734390a(21) =17515357533a(22) =64128879398a(23) =235682969485a(24) =869175349090