A067289 Numbers k such that the number of divisors of k is floor(prime(k)/k).

5, 7, 11, 25, 33, 34, 35, 38, 39, 46, 51, 55, 57, 58, 62, 65, 81, 207, 212, 236, 242, 243, 244, 245, 261, 268, 275, 279, 284, 292, 316, 325, 332, 333, 338, 356, 363, 369, 387, 388, 404, 412, 423, 425, 428, 436, 729, 1065, 1066, 1070, 1074, 1085, 1086, 1090

Offset: 1

Author

Benoit Cloitre, Feb 24 2002

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000005, A038605.

Programs

Mathematica

Select[Range[1000], DivisorSigma[0, #] == Floor[Prime[#]/#] &] (* Amiram Eldar, Apr 23 2022 *)

Formula

Numbers k such that A000005(k) = floor(prime(k)/k).