A080591 a(n) is taken to be the smallest positive integer greater than a(n-1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is congruent to 3 mod 4".

1, 3, 4, 7, 11, 12, 13, 15, 16, 17, 18, 19, 23, 27, 28, 31, 35, 39, 43, 47, 48, 49, 50, 51, 52, 53, 54, 55, 59, 60, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 83, 87, 91, 95, 99, 103, 107, 111, 112, 113, 114, 115, 119, 123, 124

Offset: 0

Author

N. J. A. Sloane, Feb 23 2003

Keywords

• easy
• nonn

Comments

The sequence of odd numbers shares many of the properties of this sequence.

Links

• 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

Crossrefs

a(n) = A080588(n+1) - 1. Cf. A079000.

Formula

a(a(n)) = 4n+3. a(2^k-1) = 2^(k+1)-1.