|
| |
|
|
A064814
|
|
Greatest common divisor of n and the n-th composite number.
|
|
7
| |
|
|
1, 2, 1, 1, 5, 6, 7, 1, 1, 2, 1, 3, 1, 2, 5, 2, 1, 2, 1, 4, 3, 2, 1, 12, 1, 13, 1, 14, 1, 15, 1, 16, 1, 2, 1, 4, 1, 1, 1, 1, 1, 6, 1, 1, 1, 1, 1, 4, 1, 10, 3, 2, 1, 2, 11, 2, 1, 1, 1, 12, 1, 2, 3, 8, 5, 1, 1, 1, 1, 5, 1, 2, 1, 2, 3, 4, 7, 2, 1, 10, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 31, 1, 1, 32, 1, 2
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| a(12) = GCD(12, A002808(12)) = GCD(12, 21) = GCD(2*2*3, 3*7) = 3.
|
|
|
LINKS
| R. Zumkeller, Table of n, a(n) for n = 1..10000 [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 22 2009]
|
|
|
FORMULA
| a(n) = GCD(n, A002808(n))
|
|
|
PROG
| (PARI) nextComp(n)= { if (!isprime(n), return(n)); return(n + 1) } { c=3; for (n=1, 1000, c=nextComp(c + 1); write("b064814.txt", n, " ", gcd(n, c)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 27 2009]
|
|
|
CROSSREFS
| Cf. A002808, A071224.
Sequence in context: A156576 A176093 A092437 * A051012 A064644 A090210
Adjacent sequences: A064811 A064812 A064813 * A064815 A064816 A064817
|
|
|
KEYWORD
| nice,nonn
|
|
|
AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 22 2001
|
| |
|
|
