A080641 a(1) = 4; for n>1, a(n) is taken to be the smallest 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 divisible by 5".

4, 6, 7, 10, 11, 15, 20, 21, 22, 25, 30, 31, 32, 33, 35, 36, 37, 38, 39, 40, 45, 50, 51, 52, 55, 56, 57, 58, 59, 60, 65, 70, 75, 76, 80, 85, 90, 95, 100, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 120, 125, 126, 127, 130, 135, 140, 145, 150, 155, 156, 157

Offset: 1

Author

N. J. A. Sloane and Benoit Cloitre, Feb 28 2003

Keywords

• nonn
• easy

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

Cf. A080639, A080640, A079000.

Formula

{a(a(n))} = {5i, i >= 2}.

Extensions

More terms from Matthew Vandermast, Feb 28 2003