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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A103333 Number of closed walks on the graph of the (7,4) Hamming code. 11
1, 3, 24, 192, 1536, 12288, 98304, 786432, 6291456, 50331648, 402653184, 3221225472, 25769803776, 206158430208, 1649267441664, 13194139533312, 105553116266496, 844424930131968, 6755399441055744, 54043195528445952, 432345564227567616 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Counts closed walks of length 2n at the degree 3 node of the graph of the (7,4) Hamming code. With interpolated zeros, counts paths of length n at this node.

a(n+1) = A157176(A016945(n)). - Reinhard Zumkeller, Feb 24 2009

For n>0: a(n) = A083713(n) - A083713(n-1). - Reinhard Zumkeller, Feb 22 2010

REFERENCES

David J.C. Mackay, Information Theory, Inference and Learning Algorithms, CUP, 2003, p. 19

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (8).

FORMULA

G.f.: (1-5*x)/(1-8*x);

a(n) = (3*8^n + 5*0^n)/8.

a(n) = 8*a(n-1) for n > 0. - Harvey P. Dale, Mar 02 2012

MAPLE

seq((3*8^n+5*`if`(n=0, 1, 0))/8, n=0..20); # Nathaniel Johnston, Jun 26 2011

MATHEMATICA

Join[{1}, NestList[8#&, 3, 20]] (* Harvey P. Dale, Mar 02 2012 *)

CROSSREFS

Cf. A082412, A103334.

Cf. A000302, A004171. - Vincenzo Librandi, Jan 22 2009

Sequence in context: A122741 A136325 A194888 * A037762 A037650 A037769

Adjacent sequences:  A103330 A103331 A103332 * A103334 A103335 A103336

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Jan 31 2005

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 December 8 14:38 EST 2019. Contains 329865 sequences. (Running on oeis4.)