cp's OEIS Frontend

A085127 Multiples of 4 which are members of A002473. Or multiples of 4 with the largest prime divisor < 10.

%I A085127 #19 Sep 23 2024 09:27:54
%S A085127 4,8,12,16,20,24,28,32,36,40,48,56,60,64,72,80,84,96,100,108,112,120,
%T A085127 128,140,144,160,168,180,192,196,200,216,224,240,252,256,280,288,300,
%U A085127 320,324,336,360,384,392,400,420,432,448,480,500,504,512,540,560,576
%N A085127 Multiples of 4 which are members of A002473. Or multiples of 4 with the largest prime divisor < 10.
%H A085127 Robert Israel, <a href="/A085127/b085127.txt">Table of n, a(n) for n = 1..10000</a>
%F A085127 a(n) = 4*A002473(n). - _Robert Israel_, Mar 18 2018
%F A085127 Sum_{n>=1} 1/a(n) = 35/32. - _Amiram Eldar_, Sep 23 2024
%p A085127 N:= 1000: # to get all terms <= N
%p A085127 sort([seq(seq(seq(seq(2^a*3^b*5^c*7^d, d=0..floor(log[7](N/(2^a*3^b*5^c)))),c=0..floor(log[5](N/(2^a*3^b)))), b=0..floor(log[3](N/2^a))), a=2..floor(log[2](N)))]); # _Robert Israel_, Mar 18 2018
%t A085127 Select[4Range[150],Last[FactorInteger[#]][[1]]<10&] (* _Harvey P. Dale_, Aug 24 2011 *)
%Y A085127 Intersection of A008586 and A002473.
%Y A085127 Cf. A085125, A085126, A085128, A085129, A080194, A085131, A085132.
%K A085127 easy,nonn
%O A085127 1,1
%A A085127 _Amarnath Murthy_, Jul 06 2003
%E A085127 More terms from _David Wasserman_, Jan 28 2005
%E A085127 Offset changed by _Robert Israel_, Mar 18 2018