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Multiples of 8 that are divisible by no prime > 5.
1

%I #17 Jun 28 2022 10:59:39

%S 0,8,16,24,32,40,48,64,72,80,96,120,128,144,160,192,200,216,240,256,

%T 288,320,360,384,400,432,480,512,576,600,640,648,720,768,800,864,960,

%U 1000,1024,1080,1152,1200,1280,1296,1440,1536,1600,1728,1800,1920,1944,2000,2048

%N Multiples of 8 that are divisible by no prime > 5.

%H Harvey P. Dale, <a href="/A108651/b108651.txt">Table of n, a(n) for n = 0..700</a>

%H N. Heninger, E. M. Rains and N. J. A. Sloane, <a href="https://arxiv.org/abs/math/0509316">On the Integrality of n-th Roots of Generating Functions</a>, arXiv:math/0509316 [math.NT], 2005-2006; J. Combinatorial Theory, Series A, 113 (2006), 1732-1745.

%F a(n) = 8*A051037(n). - _Michel Marcus_, Jun 21 2022

%F Sum_{n>=1} 1/a(n) = 15/32. - _Amiram Eldar_, Jun 28 2022

%t Select[8*Range[0,300],Max[FactorInteger[#][[All,1]]]<6&] (* _Harvey P. Dale_, Oct 10 2016 *)

%Y Cf. A051037.

%K nonn

%O 0,2

%A _N. J. A. Sloane_ and _Nadia Heninger_, Jul 08 2005