A188070 Positions of 1 in A188068; complement of A188069.

2, 3, 5, 6, 7, 9, 10, 11, 13, 14, 16, 17, 18, 20, 21, 22, 24, 25, 26, 28, 29, 31, 32, 33, 35, 36, 37, 39, 40, 41, 43, 44, 46, 47, 48, 50, 51, 52, 54, 55, 57, 58, 59, 61, 62, 63, 65, 66, 67, 69, 70, 72, 73, 74, 76, 77, 78, 80, 81, 82, 84, 85, 87, 88, 89, 91, 92, 93, 95, 96, 97, 99, 100, 102, 103, 104, 106, 107, 108, 110, 111, 113, 114, 115, 117, 118, 119, 121, 122, 123, 125

Offset: 1

Author

Clark Kimberling, Mar 20 2011

Keywords

• nonn

Comments

Cf. A188014, A188068.

Also positions of 3 in A007538. - Reinhard Zumkeller, Feb 14 2012

From Peter G. Anderson, Aug 24 2012: (Start)

a(n) = ceiling(n*x) where x = (1+sqrt(3))/2;

continued fraction of x is [1,2,1,2,1,2,...]. (End)

Conjectured partial sums of A245222. - Sean A. Irvine, Jun 26 2022

Crossrefs

Cf. A188014, A188068, A188069.

A215781 is ceiling(n*(sqrt(3)-1)).

Programs

Haskell

a188070 n = a188070_list !! (n-1)
a188070_list = filter ((== 3) . a007538) [1..]
-- Reinhard Zumkeller, Feb 14 2012

J

>. (2 %~ 1 + %:3) * i.100  NB. Peter G. Anderson, Aug 24 2012

Mathematica

(* See A188068. *)