OFFSET
1,2
COMMENTS
Equivalently, numbers k such that the k-th Catalan number C(2*k,k)/(k+1) is divisible by k^5.
The asymptotic density of this sequence is 2.83248121476... * 10^(-10) (Ford and Konyagin, 2021). - Amiram Eldar, Jan 26 2021
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..123 (terms < 10^13).
Kevin Ford and Sergei Konyagin, Divisibility of the central binomial coefficient binomial(2n, n), Trans. Amer. Math. Soc., Vol. 374, No. 2 (2021), pp. 923-953; arXiv preprint, arXiv:1909.03903 [math.NT], 2019-2020.
EXAMPLE
The central binomial coefficient C(2*84331608790,84331608790) is divisible by 84331608790^5.
CROSSREFS
KEYWORD
nonn
AUTHOR
Lucian Craciun, Feb 28 2017
EXTENSIONS
a(3)-a(20) from Giovanni Resta, Mar 03 2017
STATUS
approved