0,1

An infinite coprime sequence defined by recursion. - Michael Somos Mar 14 2004

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

L. E. Dickson, History of the Theory of Numbers. Carnegie Institute Public. 256, Washington, DC, Vol. 1, 1919; Vol. 2, 1920; Vol. 3, 1923, see vol. 1, p. 397.

E. Lucas, Nouveaux theoremes d'arithmetique superieure, Comptes Rend., 83 (1876), 1286-1288.

a(n)=L(2*3^n)+1 where L=Lucas numbers.

a(n)=L(3^(n+1))/L(3^n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 18 2005

a(n) = A001999(n)+1 (Conjecture). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 22 2007

(PARI) a(n)=if(n<1, 4*(n==0), a(n-1)^3-3*a(n-1)^2+3)

(PARI) a(n)=if(n<0, 0, n=2*3^n; fibonacci(n+1)+fibonacci(n-1)+1)

Sequence in context: A000863 A058348 A023994 this_sequence A104159 A039921 A081852

Adjacent sequences: A002810 A002811 A002812 this_sequence A002814 A002815 A002816

nonn,easy,nice

N. J. A. Sloane (njas(AT)research.att.com).