A271486 Maximal term of TRIP-Stern sequence of level n corresponding to permutation triple (e,13,23).
1, 2, 3, 4, 6, 8, 11, 16, 22, 30, 43, 60, 82, 113, 162, 224, 306, 435, 610, 836, 1168, 1637, 2282, 3120, 4399, 6131, 8522, 11812, 16561, 22933, 31810, 44468, 62335, 85639, 119452, 167281, 233169, 320747, 449700, 626513, 872175
Offset: 0
Links
- 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.
Crossrefs
Programs
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Maple
A271486T := proc(n) option remember; local an ; 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: A271486 := proc(n) local a,l,nmax; a := 0 ; for l from 2^n to 2^(n+1)-1 do nmax := max( op(A271486T(l)) ); a := max(a,nmax) ; end do: a ; end proc: # R. J. Mathar, Apr 16 2016
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Mathematica
A271487T[n_] := A271487T[n] = Module[{an}, If[n == 1, {1, 1, 1}, an = A271487T[Floor[n/2]]; If[EvenQ[n], {an[[1]] + an[[3]], an[[3]], an[[2]]}, {an[[1]], an[[1]] + an[[3]], an[[2]]}]]]; a[n_] := a[n] = Module[{a = 0, l, nMax}, For[l = 2^n, l <= 2^(n + 1) - 1, l++, nMax = Max[A271487T[l]]; a = Max[a, nMax]]; a]; Table[Print["a(", n, ") = ", a[n]]; a[n], {n, 0, 19}] (* Jean-François Alcover, Nov 17 2017, after R. J. Mathar *)
Extensions
a(20)-a(40) from Lars Blomberg, Jan 08 2018