A335119 Number of positive terms of A082916 not exceeding 10^n.

5, 33, 233, 1734, 13487, 111460, 950039, 8282970, 73631430, 662319904, 6022446576, 55201746383

Offset

1,1

Links

Table of n, a(n) for n=1..12.

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

Cf. A000984, A082916.

Sequence in context: A361237 A162816 A128418 * A284733 A001887 A118803

Adjacent sequences: A335116 A335117 A335118 * A335120 A335121 A335122

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