login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A075876 Values of n for which A075825(n)=1. 0
0, 2, 4, 12, 52, 212, 852, 3412, 13652, 54612, 218452, 873812, 3495252, 13981012 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For n > 4 it appears that a(n) = 4a(n-1) + 4.

From Robert Israel, Nov 08 2016: (Start)

By induction, we have for k >= 0:

  A075825((10*4^k-7)/3) = 2^(k+1)

  A075825((10*4^k-4)/3) = 1

  A075825((10*4^k-1)/3) = 2^(k+1)+1

  A075825((20*4^k-8)/3) = 2^(k+1)-1

  A075825((20*4^k-5)/3) = 2^(k+1)+1

  A075825((20*4^k-1)/3) = 2^(k+1)

In particular, this sequence contains b(k) = (10*4^k-4)/3 which is the solution of b(k) = 4*b(k-1)+4 with b(0) = 2.

The only terms <= 2*10^7 that are not of that form are 0 and 4. (End)

LINKS

Table of n, a(n) for n=1..14.

CROSSREFS

Cf. A075825.

Sequence in context: A030924 A030831 A058767 * A222470 A227037 A158569

Adjacent sequences:  A075873 A075874 A075875 * A075877 A075878 A075879

KEYWORD

nonn

AUTHOR

John W. Layman, Oct 16 2002

EXTENSIONS

a(10)-a(14) from Robert Israel, Nov 08 2016

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 28 17:43 EDT 2020. Contains 337393 sequences. (Running on oeis4.)