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A139270 Twice nonprime numbers. 4
2, 8, 12, 16, 18, 20, 24, 28, 30, 32, 36, 40, 42, 44, 48, 50, 52, 54, 56, 60, 64, 66, 68, 70, 72, 76, 78, 80, 84, 88, 90, 92, 96, 98, 100, 102, 104, 108, 110, 112, 114, 116, 120, 124, 126, 128, 130, 132, 136, 138, 140, 144, 148, 150 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Besides a(1), is this sequence a subset of A091375? - Bill McEachen, Dec 18 2016

LINKS

Table of n, a(n) for n=1..54.

FORMULA

a(n) = A018252(n)*2.

PROG

(PARI) is(n)=n%2==0 && !isprime(n/2) && n \\ Charles R Greathouse IV, Feb 21 2017

CROSSREFS

Cf. A018252.

Sequence in context: A108059 A276932 A180634 * A176100 A285658 A284802

Adjacent sequences:  A139267 A139268 A139269 * A139271 A139272 A139273

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, May 16 2008

STATUS

approved

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Last modified September 16 12:41 EDT 2019. Contains 327113 sequences. (Running on oeis4.)