A061708 Smallest number whose square has (2n - 1)^2 divisors.
1, 6, 36, 216, 210, 7776, 46656, 1260, 1679616, 10077696, 7560, 362797056, 44100, 18480, 78364164096, 470184984576, 272160, 264600, 101559956668416, 1632960, 3656158440062976, 21936950640377856, 180180, 789730223053602816, 9261000, 58786560, 170581728179578208256
Offset: 1
Keywords
Examples
For n = 8, a(8) = 1260 = 2*2*3*3*5*7 and d(1260^2) = d(2*2*2*2*3*3*3*3*5*5*7*7) = 225 = (2*8-1)^2. For n = 14, a(14) = 18480 and d((2*2*2*2*2*2*2*2*3*5*7*11)^2) = 729 = (2*14-1)^2.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..68
Formula
Extensions
More terms from David Wasserman, Jun 24 2002
Edited by Charlie Neder, Jun 03 2019
a(26)-a(27) from Amiram Eldar, Dec 03 2023
Comments