A040200 - OEIS

%I #22 Nov 29 2023 05:20:35

%S 14,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,

%T 1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,

%U 28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1,28,1,1,1

%N Continued fraction for sqrt(215).

%H <a href="/index/Con#confC">Index entries for continued fractions for constants</a>.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,1).

%F From _Amiram Eldar_, Nov 29 2023: (Start)

%F Multiplicative with a(2) = 1, a(2^e) = 28 for e >= 2, and a(p^e) = 1 for an odd prime p.

%F Dirichlet g.f.: zeta(s) * (1 + 27/4^s). (End)

%p with(numtheory): Digits := 300: convert(evalf(sqrt(215)),confrac);

%t ContinuedFraction[Sqrt[215],90] (* _Harvey P. Dale_, Nov 24 2011 *)

%t PadRight[{14},90,{28,1,1,1}] (* _Harvey P. Dale_, Aug 05 2021 *)

%K nonn,cofr,easy,mult

%O 0,1

%A _N. J. A. Sloane_