A141044 Two 2's followed by all 1's.

2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset: 0

Author

Paul Curtz, Jul 31 2008

Keywords

• nonn
• easy

Comments

Essentially the same as the "all ones" sequence A000012. - M. F. Hasler, May 30 2020

Examples

			Equals 199/900 = .2211111111111111... - _Bernard Schott_, May 30 2020
		

Links

• Wikipedia, Hyperoperation
• Index entries for linear recurrences with constant coefficients, signature (1).

Crossrefs

Cf. A000012, A054871.

Programs

Mathematica

PadRight[{2,2},120,1] (* Harvey P. Dale, Jan 02 2022 *)

PARI

a(n)=if(n>1,1,2) \\ Charles R Greathouse IV, Oct 07 2015

PARI

apply( {A141044(n)=(n<2)+1}, [0..90]) \\ M. F. Hasler, May 30 2020

Formula

G.f.: 2*(1+x)-x^2/(x-1). - R. J. Mathar, May 10 2001

a(n) = H_n(1, 1), where H_n is the n-th hyperoperator (cf. A054871). - Natan Arie Consigli, Feb 26 2015

a(n) = A000012(n) for all n > 1. - M. F. Hasler, May 30 2020

Extensions

Edited by N. J. A. Sloane, Mar 03 2010