A278615 Sum of terms in level n of TRIP - Stern sequence associated with permutation triple (e,13,23).
3, 8, 21, 56, 148, 394, 1044, 2776, 7364, 19568, 51936, 137960, 366256, 972736, 2582736, 6858880, 18212288, 48363680, 128423232, 341027456, 905565760, 2404701952, 6385502208, 16956417664, 45026632448, 119565922304, 317499868416, 843103631360, 2238811202560, 5945037720064, 15786698462208, 41920680589312, 111317928707072
Offset: 0
Keywords
Links
- Georg Fischer, Table of n, a(n) for n = 0..1000
- I. Amburg, K. Dasaratha, L. Flapan, T. Garrity, C. Lee, C. Mihailak, N. Neumann-Chun, S. Peluse, M. Stoffregen, Stern Sequences for a Family of Multidimensional Continued Fractions: TRIP-Stern Sequences, arXiv:1509.05239 [math.CO], 17 Sep 2015.
- Index entries for linear recurrences with constant coefficients, signature (2,4,-6).
Programs
-
Maple
A278615T := proc(n) option remember; local an, nrecur ; if n = 1 then [1, 1, 1] ; else an := procname(floor(n/2)) ; if type(n, 'even') then # apply F0 [op(1, an)+ op(3, an),op(3, an), op(2, an)] ; else # apply F1 [op(1, an), op(1, an)+ op(3, an),op(2, an)] ; end if; end if; end proc; A278615 := proc(n) local a, l; a := 0 ; for l from 2^n to 2^(n+1)-1 do L := A278615T(l) ; a := a+ L[1]+L[2]+L[3] ; end do: a ; end proc: # R. J. Mathar, Dec 02 2016
-
Mathematica
LinearRecurrence[{2, 4, -6}, {3, 8, 21}, 20] (* Jean-François Alcover, Nov 22 2017, after R. J. Mathar's g.f. *)
Formula
G.f.: ( 3+2*x-7*x^2 ) / ( 1-2*x-4*x^2+6*x^3 ). - R. J. Mathar, Dec 02 2016
Extensions
More terms from R. J. Mathar, Dec 02 2016