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A080646 a(1) = 3; for n>1, a(n) is taken to be the smallest integer greater than a(n-1) which is consistent with the condition "if n is a member of the sequence then a(n) is divisible by 3". 0
3, 4, 8, 12, 13, 14, 15, 16, 17, 18, 19, 20, 24, 28, 32, 36, 40, 44, 48, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 148, 152, 156, 160, 164, 168 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..73.

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)

Index entries for sequences of the a(a(n)) = 2n family

FORMULA

For k>=2 and i=0, ..., 4^k/2, a((4/3)*(4^(k-1)-1) + i) = (5*4^k-8)/6 + i, a((5*4^k-8)/6 + i) = (4/3)*(4^k-1) + 4*i. - N. J. A. Sloane, Mar 02 2003

{a(a(n))} = {4i, i >= 2}.

CROSSREFS

Cf. A080639, A080640, A079000.

Sequence in context: A161538 A319980 A170885 * A187579 A050102 A022432

Adjacent sequences:  A080643 A080644 A080645 * A080647 A080648 A080649

KEYWORD

nonn,easy

AUTHOR

Benoit Cloitre, Feb 12 2003

STATUS

approved

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Last modified August 2 12:30 EDT 2021. Contains 346424 sequences. (Running on oeis4.)