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A162731 The n-th number which is a product of three primes minus its central prime factor. +0
1
6, 10, 15, 18, 24, 26, 27, 39, 42, 42, 45, 50, 60, 63, 66, 65, 70, 74, 75, 90, 91, 96, 99, 100, 105, 111, 114, 114, 122, 120, 125, 135, 140, 146, 150, 147, 162, 160, 165, 168, 170, 171, 170, 175, 183, 186, 185, 190, 204, 210, 219, 225, 224, 234, 231, 231, 242, 238, 243, 250 (list; graph; listen)
OFFSET

1,1

FORMULA

a(n)=A014612(n)-A162361(n).

EXAMPLE

a(1)=6=2*2*2-2. a(2)=10=2*2*3-2. a(3)=15=2*3*3-3. a(4)=18=2*2*5-2. a(5)=24=3*3*3-3.

CROSSREFS

Cf. A014612, A162361.

Sequence in context: A151975 A094564 A166160 this_sequence A145286 A006987 A157937

Adjacent sequences: A162728 A162729 A162730 this_sequence A162732 A162733 A162734

KEYWORD

nonn,less

AUTHOR

Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jul 12 2009

EXTENSIONS

Definition reformulated, a(11), a(38) etc. corrected by R. J. mathar (mathar(AT)strw.leidenuniv.nl), Jul 16 2009

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.


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