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!)
A225846 Denominator of c(n) = 2^(2*n)*(2^(2*n) - 1)/(2*n)!, a coefficient used in the expansion of tan(x) as Sum_{n>=1} c(n)*|Bernoulli(2*n)|*x^(2*n-1). 2
1, 1, 1, 5, 21, 4725, 1485, 14189175, 42567525, 516891375, 11249435925, 714620417135625, 2124921731625, 16025362854266390625, 605758715891269565625, 5703572324950265390625, 480509193164339417203125, 22913080876041525109331015625, 92765509619601316232109375 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
REFERENCES
George Boros and Victor H. Moll, Irresistible integrals, Cambridge University Press (2006), p. 63.
LINKS
MATHEMATICA
Table[2^(2*n)*(2^(2*n)-1)/(2*n)! // Denominator, {n, 0, 20}]
PROG
(Magma) [Denominator(2^(2*n)*(2^(2*n)-1)/Factorial(2*n)): n in [0..20]]; // Vincenzo Librandi, Jul 17 2013
CROSSREFS
Cf. A225845 (numerators), A000367, A002445, A002430, A036279.
Sequence in context: A193324 A220002 A156860 * A247937 A343840 A270406
KEYWORD
nonn,frac,easy
AUTHOR
STATUS
approved

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 10:22 EDT 2024. Contains 371268 sequences. (Running on oeis4.)