A079351 a(1)=3; for n > 1, a(n) is the smallest integer greater than a(n-1) consistent with the condition "n is in the sequence if and only if a(n) is congruent to 0 (mod 5)".

3, 4, 5, 10, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115

Offset: 1

Author

Benoit Cloitre, Feb 23 2003

Keywords

• nonn
• changed

Comments

Equivalently: unique monotonic sequence satisfying a(1)=3, a(a(n))=5n.

Links

• Benoit Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, J. Integer Seqs., Vol. 6 (2003), #03.2.2.
• Benoit Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, arXiv:math/0305308 [math.NT], 2003.
• Index entries for sequences of the a(a(n)) = 2n family

Crossrefs

Cf. A079000, A080589, A003605.

Formula

a(3*5^k + j) = 5^(k+1) + 3j + 2|j|, k >= 0, -2*5^k <= j < 2*5^k.

Extensions

More terms from Matthew Vandermast, Mar 13 2003