A068350 Numbers n such that n*tau(n) > prime(2*n) where tau(n) = A000005(n).

60, 72, 84, 90, 120, 144, 168, 180, 192, 210, 216, 240, 252, 264, 270, 280, 288, 300, 312, 324, 330, 336, 360, 378, 384, 390, 396, 408, 420, 432, 440, 450, 456, 462, 468, 480, 504, 510, 520, 528, 540, 560, 576, 588, 600, 612, 624, 630, 648, 660, 672, 684

Offset: 1

Author

Benoit Cloitre, Feb 28 2002

Keywords

• easy
• nonn

Comments

The first odd term is a(232) = 2835. - Harvey P. Dale, Feb 20 2016

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000005.

Programs

Mathematica

Select[Range[800],# DivisorSigma[0,#]>Prime[2#]&] (* Harvey P. Dale, Feb 20 2016 *)

PARI

for(n=1,1000, if(n*numdiv(n)>prime(2*n),print1(n,",")))