

A002444


Denominator in Feinler's formula for unsigned Bernoulli number B_{2n}.
(Formerly M4191 N1747)


5



1, 6, 30, 84, 90, 132, 5460, 360, 1530, 7980, 13860, 8280, 81900, 1512, 3480, 114576, 117810, 1260, 3838380, 32760, 568260, 1191960, 869400, 236880, 9746100, 525096, 629640, 351120, 198360, 42480, 1362881520, 4324320, 1093950, 33008220, 434700, 843480, 46233287100, 102702600, 1081080
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OFFSET

0,2


COMMENTS

A002443/A002444 = B_{2n} (see also A000367/A002445).


REFERENCES

H. T. Davis, Tables of the Mathematical Functions. Vols. 1 and 2, 2nd ed., 1963, Vol. 3 (with V. J. Fisher), 1962; Principia Press of Trinity Univ., San Antonio, TX, Vol. 2, p. 208.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=0..38.
H. T. Davis, Tables of the Mathematical Functions, Vols. 1 and 2, 2nd ed., 1963, Vol. 3 (with V. J. Fisher), 1962; Principia Press of Trinity Univ., San Antonio, TX. [Annotated scan of pages 204208 of Volume 2.]
Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
Index entries for sequences related to Bernoulli numbers.


FORMULA

Let p_i denote the ith prime, and let V(n,i) = floor(n/(prime(i)1)) = A266742(n,i).
Then a(n) = (Prod_i (p_i)^V(n,i))/n!.
(See Davis, Vol. 2, p. 206, first displayed equation, where a(n) appears as d_{2k}.)


MAPLE

with(numtheory);
g:=proc(m) local i, n; n:=2*m;
mul(ithprime(i)^floor(n/(ithprime(i)1)), i=1..pi(n+1));
%/n!;
end;
[seq(g(m), m=0..40)]; # N. J. A. Sloane, Jan 08 2016


CROSSREFS

Cf. A002443, A000367, A002445, A266742, A266743, A266911.
Sequence in context: A258903 A050972 A259918 * A152788 A055112 A094143
Adjacent sequences: A002441 A002442 A002443 * A002445 A002446 A002447


KEYWORD

nonn,frac


AUTHOR

N. J. A. Sloane.


EXTENSIONS

Name amended upon suggestion by T. D. Noe, by M. F. Hasler, Jan 05 2016
Edited with new definition, more terms, and scan of source by N. J. A. Sloane, Jan 08 2016


STATUS

approved



