A271893 - OEIS

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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A271893

Expansion of (2*x+1)*(1-x) / ( 1-2*x-4*x^2+6*x^3 ).

1, 3, 8, 22, 58, 156, 412, 1100, 2912, 7752, 20552, 54640, 144976, 385200, 1022464, 2715872, 7210400, 19149504, 50845376, 135026368, 358537216, 952107648, 2528205952, 6713619200, 17827416320, 47340073728, 125708097536, 333811992064, 886415931904, 2353831246848, 6250454268928, 16597737933824

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

Sum of all first 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..31.

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((2*x+1)*(1-x)/(1-2*x-4*x^2+6*x^3)) \\ Altug Alkan, Apr 16 2016

CROSSREFS

Cf. A271486 (maximum at level n).

Sequence in context: A020962 A027243 A110239 * A001853 A217898 A003227

Adjacent sequences: A271890 A271891 A271892 * A271894 A271895 A271896

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Apr 16 2016

STATUS

approved