A035034 Numbers k such that k >= d(k)^2, where d(k) is the number of divisors of k.

1, 5, 7, 9, 11, 13, 17, 19, 21, 22, 23, 25, 26, 27, 29, 31, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 81

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..10000

Crossrefs

Complement of A034884.

Cf. A000005, A035033, A035035.

Programs

Mathematica

Select[Range[100],#>=DivisorSigma[0,#]^2&] (* Harvey P. Dale, May 05 2017 *)

Formula

a(n) = n + 52 for n >= 1209. - Amiram Eldar, Aug 29 2020