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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A271894 Expansion of (1+x-3*x^2) / ( 1-2*x-4*x^2+6*x^3 ). 1
1, 3, 7, 20, 50, 138, 356, 964, 2524, 6768, 17848, 47624, 126032, 335472, 889328, 2364352, 6273184, 16667808, 44242240, 117516608, 311995328, 828603648, 2200088960, 5842620544, 15513975040, 41197898496, 109395973888, 290499691520, 771395887616 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Sum of all second elements at level n of the TRIP-Stern sequence corresponding to the permutation triple (e,13,23)

LINKS

Table of n, a(n) for n=0..28.

Ilya Amburg, Krishna Dasaratha, Laure Flapan, Thomas Garrity, Chansoo Lee, Cornelia Mihaila, Nicholas Neumann-Chun, Sarah Peluse, Matthew Stoffregen, Stern Sequences for a Family of Multidimensional Continued Fractions: TRIP-Stern Sequences, arXiv:1509.05239 [math.CO], 2015, Section 7.2.1

Index entries for linear recurrences with constant coefficients, signature (2,4,-6).

FORMULA

a(n) >= 2^n.

PROG

(PARI) x='x+O('x^99); Vec((1+x-3*x^2)/(1-2*x-4*x^2+6*x^3)) \\ Altug Alkan, Apr 16 2016

CROSSREFS

Cf. A271486 (maximum at level n).

Sequence in context: A173400 A281971 A230352 * A066315 A058499 A003097

Adjacent sequences:  A271891 A271892 A271893 * A271895 A271896 A271897

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Apr 16 2016

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 April 20 06:19 EDT 2019. Contains 322294 sequences. (Running on oeis4.)