A175019 a(0)=a(1)=1; a(n) = a(n-a(n-2)) + 2.

1, 1, 3, 5, 3, 3, 7, 5, 3, 5, 7, 9, 5, 5, 7, 9, 7, 5, 11, 9, 7, 7, 11, 9, 7, 9, 11, 13, 7, 9, 11, 13, 9, 9, 11, 13, 11, 9, 15, 13, 11, 9, 15, 13, 11, 11, 15, 13, 11, 13, 15, 17, 11, 13, 15, 17, 11, 13, 15, 17, 13, 13, 15, 17, 15, 13, 19, 17, 15, 13, 19, 17, 15, 13, 19, 17, 15, 15, 19, 17

Offset: 0

Author

José María Grau Ribas, Apr 04 2010

Keywords

• nonn

Comments

Conjectures from Chai Wah Wu, Jun 12 2016: (Start)

All odd numbers appear in sequence.

2n+1 appears 2n+2 times.

a((n+3)^2-8) = 2n+1 is the last time 2n+1 appears.

For n > 0, a((n-1)^2+2) = 2n+1 is the first time 2n+1 appears. (End)

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A028884.

Programs

Mathematica

a[0] = a[1] = 1; a[n_] := a[n] = a[n - a[n - 2]] + 2; Table[a[n], {n, 0, 200}]