A363152 - OEIS

A363152

a(n) = denominator(Sum_{j=0..2*n} Bernoulli(j, 1) * Bernoulli(2*n - j, 1)).

1, 12, 180, 630, 2100, 3465, 6306300, 30030, 2187900, 101846745, 355655300, 133855722, 121808707020, 10140585, 194090796900, 46329473220030, 4870754760300, 300840735195, 384913687052594700, 2473579378270, 100402586963979300, 27473798796507063, 17194486321623468

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

OFFSET

0,2

COMMENTS

Conjecture: a(n) is cubefree. (An integer is cubefree if it is not divisible by the cube of a prime number.)

LINKS

Table of n, a(n) for n=0..22.

FORMULA

a(n) = A363151(2*n).

EXAMPLE

r(n) = 1, 7/12, -7/180, 23/630, -121/2100, 481/3465, -3015581/6306300, 67337/30030, ...

MAPLE