A068335 Numbers k such that 3^tau(k) <= k < 2*3^tau(k).
11, 13, 17, 49, 82, 85, 86, 87, 91, 93, 94, 95, 106, 111, 115, 118, 119, 122, 123, 125, 129, 133, 134, 141, 142, 143, 145, 146, 155, 158, 159, 161, 747, 764, 772, 775, 788, 796, 801, 833, 844, 845, 847, 867, 873, 892, 908, 909, 916, 925, 927, 931, 932, 956
Offset: 1
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
q[k_] := Module[{m = 3^DivisorSigma[0, k]}, m <= k < 2*m]; Select[Range[1000], q] (* Amiram Eldar, May 09 2025 *) -
PARI
isok(k) = {my(m = 3^numdiv(k)); m <= k && k < 2*m;} \\ Amiram Eldar, May 09 2025
Extensions
Name corrected by Sean A. Irvine, Feb 10 2024