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!)
A129719 Triangle read by rows: T(n,k) is the number of Fibonacci binary words of length n and having k 0's in odd positions (0 <= k <= ceiling(n/2)). A Fibonacci binary word is a binary word having no 00 subword. 3
1, 1, 1, 2, 1, 2, 2, 1, 4, 3, 1, 4, 5, 3, 1, 8, 8, 4, 1, 8, 12, 9, 4, 1, 16, 20, 13, 5, 1, 16, 28, 25, 14, 5, 1, 32, 48, 38, 19, 6, 1, 32, 64, 66, 44, 20, 6, 1, 64, 112, 104, 63, 26, 7, 1, 64, 144, 168, 129, 70, 27, 7, 1, 128, 256, 272, 192, 96, 34, 8, 1, 128, 320, 416, 360, 225, 104, 35 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Row n has 1+ceiling(n/2) terms.

LINKS

Table of n, a(n) for n=0..77.

FORMULA

G.f.: G(t,z) = (1+z)(1+tz-tz^2)/(1-(2+t)z^2+tz^4). The trivariate generating function H(t,s,z), where t marks number of 0's in odd position and s marks number of 0's in even position, is given by H(t,s,z) = (1+(1+t)z-tsz^3)/(1-(1+t+s)z^2+tsz^4).

Row sums are the Fibonacci numbers (A000045).

T(2n,k) = T(2n-1,k) + T(2n-2,k) (n >= 1).

T(2n,k) = A129721(2n,k).

Sum_{k=0..ceiling(n/2)} k*T(n,k) = A129720(n).

EXAMPLE

T(6,2)=4 because we have 110101, 011101, 010110 and 010111.

Triangle starts:

  1;

  1, 1;

  2, 1;

  2, 2, 1;

  4, 3, 1;

  4, 5, 3, 1;

  8, 8, 4, 1;

MAPLE

G:=(1+z)*(1+t*z-t*z^2)/(1-(2+t)*z^2+t*z^4): Gser:=simplify(series(G, z=0, 20)): for n from 0 to 17 do P[n]:=sort(coeff(Gser, z, n)) od: for n from 0 to 17 do seq(coeff(P[n], t, j), j=0..ceil(n/2)) od; # yields sequence in triangular form

CROSSREFS

Cf. A000045, A129720, A129721.

Sequence in context: A035436 A242210 A035369 * A062602 A123148 A173410

Adjacent sequences:  A129716 A129717 A129718 * A129720 A129721 A129722

KEYWORD

nonn,tabf

AUTHOR

Emeric Deutsch, May 13 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 October 6 03:14 EDT 2022. Contains 357261 sequences. (Running on oeis4.)