A050416 a(1)=a(2)=1, then a(n+1) = floor(a(n)/3) if this is not among 0, a(1), ..., a(n); otherwise a(n+1) = a(n) + a(n-1).

1, 1, 2, 3, 5, 8, 13, 4, 17, 21, 7, 28, 9, 37, 12, 49, 16, 65, 81, 27, 108, 36, 144, 48, 192, 64, 256, 85, 341, 113, 454, 151, 50, 201, 67, 22, 89, 29, 118, 39, 157, 52, 209, 69, 23, 92, 30, 10, 40, 50, 90, 140, 46, 15, 61, 20, 6, 26, 32

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Comments

Numbers appearing among the terms more than once include 1, 50, 265, 341, 516, 570, 622, ... - Ivan Neretin, Sep 04 2015

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A050417.

Cf. A050000, A050004, A050076, A050080, A050084, A050104, A050124, A050128, A050132, A050135, A050136, A050137, A050138, A050139, A050170, A050196.

Programs

Mathematica

a = {0, 1, 1}; Do[AppendTo[a, If[MemberQ[a, c = Quotient[a[[-1]], 3]], a[[-1]] + a[[-2]], c]], {n, 3, 59}]; Delete[a, 1] (* Ivan Neretin, Sep 04 2015 *)