OFFSET
1,1
LINKS
Kevin Ford and Sergei Konyagin, Divisibility of the central binomial coefficient binomial(2n, n), arXiv:1909.03903 [math.NT], 2019. See Table 2.
FORMULA
a(n) ~ c * 10^n/log(10^n), where c = 1.526453... (Ford and Konyagin, 2019).
EXAMPLE
Below 10 there are 5 positive terms of A082916: 1, 3, 5, 7, 9. Therefore a(1) = 5.
MATHEMATICA
seqQ[n_] := CoprimeQ[Binomial[2*n, n], n]; seq = {}; p = 10; c = 0; Do[If[seqQ[n], c++]; If[n == p, p *= 10; AppendTo[seq, c]], {n, 1, 10^5}]; seq
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, May 24 2020
EXTENSIONS
Terms a(4)-a(11) were taken from the paper by Ford and Konyagin (2019).
a(12) from Giovanni Resta, May 24 2020
STATUS
approved