login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A066560 Smallest composite number divisible by n. 2
4, 4, 6, 4, 10, 6, 14, 8, 9, 10, 22, 12, 26, 14, 15, 16, 34, 18, 38, 20, 21, 22, 46, 24, 25, 26, 27, 28, 58, 30, 62, 32, 33, 34, 35, 36, 74, 38, 39, 40, 82, 42, 86, 44, 45, 46, 94, 48, 49, 50, 51, 52, 106, 54, 55, 56, 57, 58, 118, 60, 122, 62, 63, 64, 65, 66, 134, 68, 69, 70 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

FORMULA

For n>=2: a(n) = 2*n if n prime; otherwise a(n) = n.

PROG

(PARI) { for (n=1, 1000, if (isprime(n), a=2*n, a=n); if (n==1, a=4); write("b066560.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Mar 02 2010]

CROSSREFS

Sequence in context: A077553 A010659 A131089 * A205031 A085050 A071256

Adjacent sequences:  A066557 A066558 A066559 * A066561 A066562 A066563

KEYWORD

nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Dec 17 2001

EXTENSIONS

More terms and formula from Francisco Salinas (franciscodesalinas(AT)hotmail.com), Dec 24 2001

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 11:36 EST 2012. Contains 205623 sequences.