login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A238163 Nearest integer to 8*(2*n+1)!*Bernoulli(2*n,1/2). 2
8, -4, 28, -930, 96012, -24144750, 12602990070, -12203470904625, 20180112406353900, -53495387545025175750, 216267236072968468547250, -1280630367874799320798794375, 10743714652441927865738713818750, -124178158916511109662405449217796875 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

See A033473 for the numerators and A238015 for the denominators of 8*(2*n+1)!*Bernoulli(2*n,1/2).

As R. Israel remarks, this expression is no longer an integer for n = 15, 23, 27, 29, 30, 31, 39, 43, 45, 46, 47,... That's why "nearest integer" has been prefixed. - M. F. Hasler, Feb 16 2014

It can be seen that the denominator of (2*n+1)!*Bernoulli(2*n,1/2) is never more than 2^log2(n+1). This yields A238164 as an alternative way of producing an integer sequence based on (2n+1)! B[2n](1/2).

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Index entries for sequences related to Bernoulli numbers.

MATHEMATICA

a[n_] := Round[ (2 n + 1)! 8 BernoulliB[2 n, 1/2]]; Array[a, 14, 0] (* Robert G. Wilson v, Feb 17 2014 *)

PROG

(PARI) A238163=n->round(8*(2*n+1)!*subst(bernpol(2*n, x), x, 1/2)) \\ M. F. Hasler, Feb 16 2014

CROSSREFS

Cf. A033473, A238015, A238164.

Sequence in context: A160415 A160411 A033473 * A213773 A213178 A082682

Adjacent sequences:  A238160 A238161 A238162 * A238164 A238165 A238166

KEYWORD

sign

AUTHOR

M. F. Hasler, Feb 18 2014

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 14:27 EDT 2019. Contains 322310 sequences. (Running on oeis4.)