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!)
A187919 a(n) = (19/28)*(3^n-1)*P(n-1)+(3/7)*(4*3^n-5)*P(n) where P() are the Pell numbers A000129. 0
3, 32, 256, 1912, 13989, 101656, 737078, 5340368, 38683143, 280179632, 2029268236, 14697327880, 106447627113, 770962306792, 5583803916866, 40441487719712, 292903169916939, 2121392429130176, 15364483152682648, 111279430895716888, 805956934031993133, 5837256482937956152, 42277151305568313806, 306198216183841310960, 2217683658862794974223 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Arises in the study of ternary strings.
REFERENCES
R. P. Grimaldi, Ternary strings with no consecutive 0's and no consecutive 1's, Congressus Numerantium, 205 (2011), 129-149. (See val_n.)
LINKS
FORMULA
G.f.: x*(6*x^2+8*x+3) / ((x^2+2*x-1)*(9*x^2+6*x-1)). - Colin Barker, Jul 25 2013
MATHEMATICA
LinearRecurrence[{8, -2, -24, -9}, {3, 32, 256, 1912}, 30] (* Harvey P. Dale, Feb 02 2020 *)
CROSSREFS
Cf. A000129 (Pell numbers).
Sequence in context: A002059 A028447 A081012 * A198320 A035533 A278303
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Mar 16 2011
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 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)