A289662 a(n) is the smallest m such that p = n-th popular prime = A385503(n) is uniquely popular on the interval [2,m] or -1 if p is never uniquely popular.

2, 12, 80, 196, 1638, 4864, 22425, 46500, 109779, 158625, 603564, 2552416, 2620142, 2627250, 41163747, 237398795, 1966466950, 13690729828, 64322158656, 79838739611, 220355987735, 232268774850, 618745972214, 1882062476406, 9607713772982, 19364051829855, 26393150937218, 37636607806688, 114514665167797, 173974642809066, 228013323978930, 259772858868378, 284600479573629, 644741545246282

Offset

1,1

Comments

See A385503 for further links and information.

Links

Table of n, a(n) for n=1..34.

Nathan McNew, Popular values of the largest prime divisor function (corrected version), page 16, November 2015.

Crossrefs

Cf. A006530, A385503, A125624, A289661-A289665.

Sequence in context: A062871 A306272 A227968 * A107632 A270775 A393295

Adjacent sequences: A289659 A289660 A289661 * A289663 A289664 A289665

Keyword

nonn

Author

N. J. A. Sloane, Jul 25 2017

Extensions

Deleted "first" from definition. - N. J. A. Sloane, Oct 03 2019

Edited, and terms updated from revised version of McNew, by Peter Munn, Jul 04 2025

Status

approved