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A085127
Multiples of 4 which are members of A002473. Or multiples of 4 with the largest prime divisor < 10.
8
4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 48, 56, 60, 64, 72, 80, 84, 96, 100, 108, 112, 120, 128, 140, 144, 160, 168, 180, 192, 196, 200, 216, 224, 240, 252, 256, 280, 288, 300, 320, 324, 336, 360, 384, 392, 400, 420, 432, 448, 480, 500, 504, 512, 540, 560, 576
OFFSET
1,1
LINKS
FORMULA
a(n) = 4*A002473(n). - Robert Israel, Mar 18 2018
Sum_{n>=1} 1/a(n) = 35/32. - Amiram Eldar, Sep 23 2024
MAPLE
N:= 1000: # to get all terms <= N
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
MATHEMATICA
Select[4Range[150], Last[FactorInteger[#]][[1]]<10&] (* Harvey P. Dale, Aug 24 2011 *)
CROSSREFS
Intersection of A008586 and A002473.
Sequence in context: A311125 A311126 A311127 * A311128 A311129 A311130
KEYWORD
easy,nonn
AUTHOR
Amarnath Murthy, Jul 06 2003
EXTENSIONS
More terms from David Wasserman, Jan 28 2005
Offset changed by Robert Israel, Mar 18 2018
STATUS
approved