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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063888 Number of n-step walks on a cube lattice starting from the origin but not returning to it at any stage. 0
1, 6, 30, 180, 1026, 6156, 35940, 215640, 1271106, 7626636, 45182124, 271092744, 1610875836, 9665255016, 57546367704, 345278206224, 2058613385346, 12351680312076, 73717606430364, 442305638582184, 2641804748619732 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n)/6^n tends to 0.65946...

REFERENCES

S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 322-331.

LINKS

Table of n, a(n) for n=0..20.

S. R. Finch, Polya's Random Walk Constants

FORMULA

a(2n) = 6*a(2n-1)-A049037(n); a(2n+1) = 6*a(2n).

EXAMPLE

a(2) = 30 since there are 36 2-step walks but 6 of them involve a return to the origin at some stage; similarly a(3) = 180 since there are 216 3-step walks but 36 of them involve a return to the origin at some stage.

CROSSREFS

Sequence in context: A089896 A057754 A001473 * A029571 A259276 A109501

Adjacent sequences:  A063885 A063886 A063887 * A063889 A063890 A063891

KEYWORD

nonn

AUTHOR

Henry Bottomley, Aug 28 2001

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 February 18 09:42 EST 2019. Contains 320249 sequences. (Running on oeis4.)