A002444 - OEIS

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A002444

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

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

(list; graph; refs; listen; history; text; internal format)

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 204-208 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 i-th 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;