0,2

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

This is the special case k=4 of sequences with exact mutual k-residues. In general, a(1)=k+1 and a(n)=min{m | m>a(n-1), mod(m,a(i))=k, i=1,...,n-1}. k=1 gives Sylvester's sequence A000058 and k=2 Fermat sequence A000215. - Seppo Mustonen (seppo.mustonen(AT)helsinki.fi), Sep 4 2005

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).

S. W. Golomb, On certain nonlinear recurring sequences, Amer. Math. Monthly 70 (1963), 403-405.

A. V. Aho and N. J. A. Sloane, Some doubly exponential sequences, Fib. Quart., 11 (1973), 429-437.

Index entries for sequences of form a(n+1)=a(n)^2 + ...

S. Mustonen, On integer sequences with mutual k-residues

a(n)=L(2^n)+2, if n>0 where L() is Lucas sequence.

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

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

a(n) = A001566(n-1)+2 (for n>0).

Cf. A000058.

Adjacent sequences: A000321 A000322 A000323 this_sequence A000325 A000326 A000327

Sequence in context: A105182 A100457 A080872 this_sequence A123817 A124421 A143554

nonn,easy

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