A225729 - OEIS

%I #7 May 14 2013 21:09:37

%S 2,3,4,6,8,9,10,12,14,15,16,18,20,24,28,30,32,36,40,42,48,54,56,60,66,

%T 70,72,78,80,84,90,96,100,108,112,120,126,132,140,144,150,156,160,168,

%U 180,192,210,216,240,252,264,270,280,288,300,312,330,336,360,396

%N Numbers n such that n < d(n)^(21/10), where d(n) is the number of divisors of n.

%C Alternatively, we could write n^10 < d(n)^21. The last odd number is a(10) = 15.

%H T. D. Noe, <a href="/A225729/b225729.txt">Table of n, a(n) for n = 1..89</a> (complete sequence)

%t t = {}; Do[If[n < DivisorSigma[0, n]^(21/10), AppendTo[t, n]], {n, 10^4}]; t

%Y Cf. A034884 (n < d(n)^2), A175495 (n < 2^d(n)), A056757 (n < d(n)^3).

%Y Cf. A225730-A225738.

%K nonn,fini,full

%O 1,1

%A _T. D. Noe_, May 14 2013