A124509 - OEIS

%I #13 Jul 11 2023 03:38:02

%S 1,6,12,24,36,48,72,96,144,192,216,288,384,432,576,768,864,1152,1296,

%T 1536,1728,2304,2592,3072,3456,4608,5184,6144,6912,7776,9216,10368,

%U 12288,13824,15552,18432,20736,24576,27648,31104,36864,41472,46656,49152,55296,62208

%N Range of A124508.

%C 1 together with numbers of the form 2^i * 3^j with i >= j >= 1. - _Amiram Eldar_, Jul 11 2023

%H Amiram Eldar, <a href="/A124509/b124509.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SmoothNumber.html">Smooth Number</a>.

%F a(n) = A124508(A124510(n)).

%F Sum_{n>=1} 1/a(n) = 7/5. - _Amiram Eldar_, Jul 11 2023

%t With[{max = 70000}, Join[{1}, Sort[Flatten[Table[2^i*3^j, {i, 1, Log2[max]}, {j, 1, Min[i, Log[3, max/2^i]]}]]]]] (* _Amiram Eldar_, Jul 11 2023 *)

%Y Subsequence of A003586.

%Y A007283 is a subsequence.

%Y Cf. A124508, A124510.

%K nonn,easy

%O 1,2

%A _Reinhard Zumkeller_, Nov 04 2006

%E Missing term a(43) inserted and more terms added by _Amiram Eldar_, Jul 11 2023