login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056469 Number of elements in the continued fraction for Sum_{k=0..n} 1/2^2^k. 5
2, 3, 4, 6, 10, 18, 34, 66, 130, 258, 514, 1026, 2050, 4098, 8194, 16386, 32770, 65538, 131074, 262146, 524290, 1048578, 2097154, 4194306, 8388610, 16777218, 33554434, 67108866, 134217730, 268435458, 536870914, 1073741826, 2147483650 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Index entries for linear recurrences with constant coefficients, signature (3,-2).

FORMULA

a(0)=2; for n > 0, a(n) = 2^(n-1) + 2 = A052548(n-1) + 2.

a(n) = floor(2^(n-1) + 2). - Vincenzo Librandi, Sep 21 2011

From Colin Barker, Mar 22 2013: (Start)

a(n) = 3*a(n-1) - 2*a(n-2) for n > 2.

G.f.: -(x^2+3*x-2) / ((x-1)*(2*x-1)). (End)

MATHEMATICA

LinearRecurrence[{3, -2}, {2, 3, 4}, 40] (* Harvey P. Dale, Apr 23 2015 *)

PROG

(Sage) [floor(gaussian_binomial(n, 1, 2)+3) for n in range(-1, 32)] # Zerinvary Lajos, May 31 2009

(Magma) [Floor(2^(n-1)+2): n in [0..60]]; // Vincenzo Librandi, Sep 21 2011

CROSSREFS

Cf. A007400. Apart from initial term, same as A052548. See also A089985.

Sequence in context: A106511 A024490 A317200 * A228863 A004047 A355191

Adjacent sequences: A056466 A056467 A056468 * A056470 A056471 A056472

KEYWORD

nonn,easy

AUTHOR

Benoit Cloitre, Dec 07 2002

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 26 21:15 EST 2022. Contains 358362 sequences. (Running on oeis4.)