login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A007516 (2^2^...^2) (n times) + 1.
(Formerly M2504)
4
1, 3, 5, 17, 65537 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(0) could equally well be taken to be 2 rather than 1, which gives A004249. - N. J. A. Sloane, Sep 14 2009

The next term already has 19729 digits and is too large to include. - Stefan Steinerberger, Apr 14 2006

REFERENCES

P. Ribenboim, The Book of Prime Number Records. Springer-Verlag, NY, 2nd ed., 1989, p. 73.

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

LINKS

Table of n, a(n) for n=0..4.

FORMULA

a(1) = 1, a(2) = 3, a(n+1) = 2^(a(n)-1) + 1. - Stefan Steinerberger, Apr 14 2006

MATHEMATICA

a[1] := 1; a[2] := 3; a[n_] := 2^(a[n - 1] - 1) + 1; Table[a[n], {n, 1, 5}] (* Stefan Steinerberger, Apr 14 2006 *)

CROSSREFS

Cf. A004249 (another version).

Sequence in context: A278735 A094487 * A249759 A039584 A191717 A136131

Adjacent sequences:  A007513 A007514 A007515 * A007517 A007518 A007519

KEYWORD

nonn

AUTHOR

N. J. A. Sloane and Robert G. Wilson v

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 22 13:18 EDT 2017. Contains 286872 sequences.