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a(n) = numerator of b(n), where b(1) = 2, b(n) = b(n-1) - 1/b(n-1).
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%I #21 Feb 11 2022 17:54:21

%S 2,3,5,-11,779,497941,181860254581,16687694789137362648661,

%T -263439569256003706800705587722279993788907979,

%U 81512663708476146329709015825571064954724426915346799560162522434680208602364731247764459

%N a(n) = numerator of b(n), where b(1) = 2, b(n) = b(n-1) - 1/b(n-1).

%C Every term of this sequence of numerators is coprime to every other term.

%H M. Chamberland and M. Martelli, <a href="https://chamberland.math.grinnell.edu/papers/mario_digits.pdf">Unbounded Orbits and Binary Digits</a>, Grinnell College.

%H Clark Kimberling, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL12/Kimberling/kimberling56.html">Polynomials associated with reciprocation</a>, JIS 12 (2009) 09.3.4

%e A127814/A127815 = 2, 3/2, 5/6, -11/30, 779/330, 497941/257070, 181860254581/128005692870, ...

%t f[l_List] := Append[l, l[[ -1]] - 1/l[[ -1]]];Numerator[Nest[f, {2}, 10]] (* _Ray Chandler_, Feb 07 2007 *)

%t Numerator/@NestList[#-1/#&,2,10] (* _Harvey P. Dale_, Apr 30 2011 *)

%Y Cf. A127815, A242995.

%K easy,frac,sign

%O 1,1

%A _Leroy Quet_, Jan 30 2007

%E Extended by _Ray Chandler_, Feb 07 2007