a(1)=1, a(2)=3, a(3)=8; for n>=4, a(n) = 10*a(n-3) + 8 (if a(n-3) is odd) or + 9 (if a(n-3) is even).

A117713

a(1)=1, a(2)=3, a(3)=8; for n>=4, a(n) = 10*a(n-3) + 8 (if a(n-3) is odd) or + 9 (if a(n-3) is even).

Terms

    a(0) =1a(1) =3a(2) =8a(3) =18a(4) =38a(5) =89a(6) =189a(7) =389a(8) =898a(9) =1898a(10) =3898a(11) =8989a(12) =18989a(13) =38989a(14) =89898a(15) =189898a(16) =389898a(17) =898989a(18) =1898989a(19) =3898989a(20) =8989898a(21) =18989898a(22) =38989898a(23) =89898989a(24) =189898989a(25) =389898989a(26) =898989898a(27) =1898989898a(28) =3898989898a(29) =8989898989

External references