a(n) = A337339(n) - n.

Terms

a(0) =0a(1) =3a(2) =10a(3) =37a(4) =20a(5) =107a(6) =54a(7) =357a(8) =304a(9) =211a(10) =74a(11) =1001a(12) =132a(13) =95a(14) =598a(15) =3265a(16) =164a(17) =2795a(18) =246a(19) =1965a(20) =1492a(21) =739a(22) =398a(23) =9089a(24) =1176a(25) =1275a(26) =7786a(27) =349a(28) =452a(29) =5483