A108047 Concatenation of the previous pair of numbers, with the first two terms both 1.

1, 1, 11, 111, 11111, 11111111, 1111111111111, 111111111111111111111, 1111111111111111111111111111111111, 1111111111111111111111111111111111111111111111111111111, 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

Offset

1,3

Comments

The Fibonacci numbers, A000045, represented in base 1 (see A000042).

Links

Paolo Xausa, Table of n, a(n) for n = 1..16

Formula

a(n) = (10^A000045(n)-1)/9.

a(n) = A000042(A000045(n)).

Example

The third term is 11 which is the concatenation of the first two terms 1 and 1.

Mathematica

(10^Fibonacci[Range[12]] - 1)/9 (* Paolo Xausa, Jun 03 2026 *)

Crossrefs

Column b=1 of A214326.

Column k=1 of A214679.

Essentially the same as A037842.

Cf. A131293.

Sequence in context: A015468 A037842 A131293 * A144784 A030175 A263805

Adjacent sequences: A108044 A108045 A108046 * A108048 A108049 A108050

Keyword

nonn,easy,base

Author

Parthasarathy Nambi, Jun 01 2005

Extensions

Edited by Jason Kimberley, Dec 15 2012

Status

approved