A080707 a(1)=5; for n>1, a(n) = smallest number > a(n-1) such that the condition "n is in the sequence if and only if a(n) is a multiple of 3" is satisfied.

5, 7, 8, 10, 12, 13, 15, 18, 19, 21, 22, 24, 27, 28, 30, 31, 32, 33, 36, 37, 39, 42, 43, 45, 46, 47, 48, 51, 52, 54, 57, 60, 63, 64, 65, 66, 69, 70, 72, 73, 74, 75, 78, 79, 81, 84, 87, 90, 91, 92, 93, 96, 97, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 111, 114, 117

Offset

1,1

Links

Table of n, a(n) for n=1..66.

B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, J. Integer Seqs., Vol. 6 (2003), #03.2.2.

B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence (math.NT/0305308)

Formula

{a(a(n))} = {3i : i >= 4}.

Crossrefs

Sequence in context: A288735 A317507 A304433 * A059612 A314372 A314373

Adjacent sequences: A080704 A080705 A080706 * A080708 A080709 A080710

Keyword

nonn,easy

Author

Benoit Cloitre, Mar 01 2003

Extensions

More terms from Matthew Vandermast, Mar 14 2003

Status

approved