a(n) = a(n-1) + a(n-2) + digsum(a(n-1)) + digsum(a(n-2)), with a(0)=0 and a(1)=1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =6a(4) =16a(5) =35a(6) =66a(7) =121a(8) =203a(9) =333a(10) =550a(11) =902a(12) =1473a(13) =2401a(14) =3896a(15) =6330a(16) =10264a(17) =16619a(18) =26919a(19) =43588a(20) =70562a(21) =114198a(22) =184804a(23) =299051a(24) =483906a(25) =783013a(26) =1266971a(27) =2050038a(28) =3317059a(29) =5367143