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A069549
Smallest composite k such that phi(k) > k*(1-1/n).
2
4, 4, 9, 25, 25, 49, 49, 121, 121, 121, 121, 169, 169, 289, 289, 289, 289, 361, 361, 529, 529, 529, 529, 841, 841, 841, 841, 841, 841, 961, 961, 1369, 1369, 1369, 1369, 1369, 1369, 1681, 1681, 1681, 1681, 1849, 1849, 2209, 2209, 2209, 2209, 2809, 2809, 2809
OFFSET
1,1
COMMENTS
Or, least composite k such that k is coprime to the n-1 numbers k+1 ... k+n-1. E.g. a(4) = 25 because 25 is coprime to 26, 27 and 28. - Amarnath Murthy, Apr 20 2004
FORMULA
a(n)=nextprime(n)^2=A007918(n)^2
CROSSREFS
Cf. A052349.
Sequence in context: A192030 A117879 A334009 * A118069 A089539 A324010
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Apr 21 2002
EXTENSIONS
Edited by David Wasserman, Apr 23 2007
STATUS
approved