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!)
A096952 Numerators of upper bounds for Lagrange remainder in Taylor's expansion of log((1+x)/(1-x)) for x=1/3, multiplied by 6/5. 3

%I #14 Apr 29 2023 23:01:35

%S 1,7,11,463,4039,35839,320503,575267,25854247,232557151,298927153,

%T 18830313487,6778577311,1525146340543,13726182847159,123535108753519,

%U 1111813831298023,2001263178349523,90056808665990167,810511140554958031

%N Numerators of upper bounds for Lagrange remainder in Taylor's expansion of log((1+x)/(1-x)) for x=1/3, multiplied by 6/5.

%C An upper bound for the Lagrange remainder in the expansion of log((1+x)/(1-x)) for x=1/3, i.e., for log(2), is R(2*n) = (1/2^(2*n+1) + 1/3^(2*n+1))/(2*n+1), n >= 0.

%C The denominators are found in A096953.

%C log(2) = 2*Sum_{k>=1} ((1/3)^(2*k-1))/(2*k-1), from the Taylor series of log((1+x)/(1-x)) for x=1/3.

%D M. Barner and F. Flohr, Analysis I, de Gruyter, 5. Auflage, 2000; p. 293.

%H W. Lang, <a href="/A096952/a096952.txt">More comments</a>.

%F a(n) = numerator(A(n)), where A(n) = (6/5)*(1/2^(2*n+1) + 1/3^(2*n+1))/(2*n+1) = A096951(n)/((2*n+1)*6^(2*n)).

%e n=3: R(2*3)=(5/6)* a(3)/A096953(3) = (5/6)*463/326592 = 2315/1959552 = 0.001181..., therefore log(2) - 2*Sum_{k=1..3} ((1/3)^(2*k-1))/(2*k-1) < 0.001181... . In fact, the partial sum is 0.0001430654... .

%K nonn,easy,frac

%O 0,2

%A _Wolfdieter Lang_, Jul 16 2004

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 April 20 00:03 EDT 2024. Contains 371798 sequences. (Running on oeis4.)