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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A133552 Number of length n binary sequences with at most 4 of every adjacent 6 bits set. 0
1, 2, 4, 8, 16, 31, 57, 109, 209, 401, 769, 1473, 2817, 5391, 10321, 19761, 37834, 72432, 138663, 265455, 508195, 972909, 1862575, 3565778, 6826437, 13068741, 25019217, 47897608, 91696751, 175547250, 336073354, 643389727, 1231726180 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (1, 1, 1, 0, 1, 2, 0, -2, -2, 0, 0, -1, 0, 0, 1).
FORMULA
Conjectures from Colin Barker, Feb 22 2018: (Start)
G.f.: (1 + x + x^2 + x^3 + 2*x^4 + 2*x^5 - 2*x^6 - 3*x^7 - 2*x^8 - x^10 - x^11 + x^13 + x^14) / (1 - x - x^2 - x^3 - x^5 - 2*x^6 + 2*x^8 + 2*x^9 + x^12 - x^15).
a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-5) + 2*a(n-6) - 2*a(n-8) - 2*a(n-9) - a(n-12) + a(n-15) for n>14.
(End)
MATHEMATICA
CoefficientList[Series[(1+x+x^2+x^3+2x^4+2x^5-2x^6-3x^7-2x^8-x^10-x^11+x^13+x^14)/(1-x-x^2-x^3-x^5-2x^6+2x^8+2x^9+x^12-x^15), {x, 0, 50}], x] (* or *) LinearRecurrence[ {1, 1, 1, 0, 1, 2, 0, -2, -2, 0, 0, -1, 0, 0, 1}, {1, 2, 4, 8, 16, 31, 57, 109, 209, 401, 769, 1473, 2817, 5391, 10321}, 50] (* Harvey P. Dale, Aug 14 2023 *)
CROSSREFS
Sequence in context: A325749 A056183 A000127 * A174439 A000128 A106399
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 24 2007
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 March 19 01:57 EDT 2024. Contains 370952 sequences. (Running on oeis4.)