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%I #13 Sep 23 2024 09:28:03
%S 6,12,18,24,30,36,42,48,54,60,72,84,90,96,108,120,126,144,150,162,168,
%T 180,192,210,216,240,252,270,288,294,300,324,336,360,378,384,420,432,
%U 450,480,486,504,540,576,588,600,630,648,672,720,750,756,768,810,840
%N Multiples of 6 which are 7-smooth.
%C Equivalently, multiples of 6 with the largest prime divisor < 10.
%F From _Amiram Eldar_, Sep 22 2024: (Start)
%F a(n) = 6*A002473(n).
%F Sum_{n>=1} 1/a(n) = 35/48. (End)
%t With[{p = Prime[Range[4]]}, 6 * Select[Range[140], Times @@ (p^IntegerExponent[#, p]) == # &]] (* _Amiram Eldar_, Sep 23 2024 *)
%Y Intersection of A008588 and A002473.
%Y Cf. A085125, A085126, A085127, A085128, A080194, A085131, A085132.
%K nonn,easy
%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 19 2024