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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A078977 Denominator of n-th convergent to e^(2/3). 1

%I #9 Dec 01 2013 13:51:14

%S 1,1,19,134,153,287,3023,163529,2619487,2783016,5402503,105430573,

%T 9494154073,237459282398,246953436471,484412718869,13810509564803,

%U 1740608617884047,59194503517622401,60935112135506448

%N Denominator of n-th convergent to e^(2/3).

%F Special cases : a(5k+1)=abs(A065923(3k)); a(5k+3)=abs(A065923(3k+2)) where A065923(n)=y(n, -3) where y(n, x)=sum (k=0, n, (n+k)!*(x/2)^k/((n-k)!*k!))

%t Denominator[Convergents[E^(2/3),20]] (* _Harvey P. Dale_, Dec 01 2013 *)

%o (PARI) a(n)=component(component(contfracpnqn(contfrac(exp(2/3),n)),1),2) (Warning: this will give only a limited number of correct terms, depending on the precision used. - The Editors, Oct 13 2009. See A078976 for better code.)

%Y Cf. A069951, A065923, A001518, A007677, A078976.

%K frac,nonn

%O 1,3

%A _Benoit Cloitre_, Dec 19 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 06:34 EDT 2024. Contains 371265 sequences. (Running on oeis4.)