

A228970


Triangle of denominators of the coefficients t(n,k) in the formula B(2n) = sum_{k=1..n1} t(n,k)*B(2k)*B(2n2k), where the B() are the evenindexed Bernoulli numbers.


2



5, 7, 7, 85, 17, 85, 341, 341, 341, 341, 455, 91, 65, 91, 455, 5461, 5461, 5461, 5461, 5461, 5461, 4369, 4369, 21845, 257, 21845, 4369, 4369, 9709, 9709, 1387, 9709, 9709, 1387, 9709, 9709
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OFFSET

2,1


COMMENTS

GCD of rows (5, 7, 17, 341, 13, 5461 ...) are Zsigmondy numbers A064080.  Paul Curtz, Sep 13 2013


REFERENCES

George Boros and Victor H. Moll, Irresistible Integrals: Symbolics, Analysis and Experiments in the Evaluation of Integrals, Cambridge University Press (2006), p. 100.


LINKS

JeanFrançois Alcover, Table of n, a(n) for n = 2..105


EXAMPLE

6/5;
5/7, 25/7;
28/85, 70/17, 588/85;
45/341, 1050/341, 4410/341, 3825/341;
...


MATHEMATICA

Table[(2^(2*k)  1)/(2^(2*n)  1)* Binomial[2*n, 2*k], {n, 2, 9}, {k, 1, n1}] // Flatten // Denominator


CROSSREFS

Cf. A228969 (numerators), A064080 (Zsigmondy numbers).
Sequence in context: A126992 A028316 A019163 * A266712 A021177 A091662
Adjacent sequences: A228967 A228968 A228969 * A228971 A228972 A228973


KEYWORD

frac,nonn,tabl


AUTHOR

JeanFrançois Alcover, Sep 10 2013


STATUS

approved



