A085131 - OEIS

%I #19 Sep 23 2024 09:28:07

%S 8,16,24,32,40,48,56,64,72,80,96,112,120,128,144,160,168,192,200,216,

%T 224,240,256,280,288,320,336,360,384,392,400,432,448,480,504,512,560,

%U 576,600,640,648,672,720,768,784,800,840,864,896,960,1000,1008,1024

%N Multiples of 8 which are 7-smooth.

%C Equivalently, multiples of 8 with the largest prime divisor < 10.

%H Harvey P. Dale, <a href="/A085131/b085131.txt">Table of n, a(n) for n = 1..1000</a>

%F From _Amiram Eldar_, Sep 22 2024: (Start)

%F a(n) = 8*A002473(n).

%F Sum_{n>=1} 1/a(n) = 35/64. (End)

%t Select[8*Range[200],FactorInteger[#][[-1,1]]<10&] (* _Harvey P. Dale_, Oct 22 2017 *)

%Y Intersection of A008590 and A002473.

%Y Cf. A085125, A085126, A085127, A085128, A085129, A080194, A085132.

%K easy,nonn

%O 1,1

%A _Amarnath Murthy_, Jul 06 2003

%E More terms from _David Wasserman_, Jan 28 2005

%E Offset changed by _Andrew Howroyd_, Sep 22 2024