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Two 2's followed by all 1's.
13

%I #52 Jan 02 2022 12:33:33

%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,

%T 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,

%U 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

%N Two 2's followed by all 1's.

%C Essentially the same as the "all ones" sequence A000012. - _M. F. Hasler_, May 30 2020

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Hyperoperation">Hyperoperation</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).

%F G.f.: 2*(1+x)-x^2/(x-1). - _R. J. Mathar_, May 10 2001

%F a(n) = H_n(1, 1), where H_n is the n-th hyperoperator (cf. A054871). - _Natan Arie Consigli_, Feb 26 2015

%F a(n) = A000012(n) for all n > 1. - _M. F. Hasler_, May 30 2020

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

%t PadRight[{2,2},120,1] (* _Harvey P. Dale_, Jan 02 2022 *)

%o (PARI) a(n)=if(n>1,1,2) \\ _Charles R Greathouse IV_, Oct 07 2015

%o (PARI) apply( {A141044(n)=(n<2)+1}, [0..90]) \\ _M. F. Hasler_, May 30 2020

%Y Cf. A000012, A054871.

%K nonn,easy

%O 0,1

%A _Paul Curtz_, Jul 31 2008

%E Edited by _N. J. A. Sloane_, Mar 03 2010