A141295 - OEIS

A141295

Largest m<=n such that all k with 1<=k<=m are divisors of n or coprime to n.

1, 2, 3, 4, 5, 3, 7, 5, 5, 3, 11, 7, 13, 3, 5, 5, 17, 3, 19, 5, 5, 3, 23, 8, 9, 3, 5, 5, 29, 3, 31, 5, 5, 3, 9, 7, 37, 3, 5, 5, 41, 3, 43, 5, 5, 3, 47, 8, 13, 3, 5, 5, 53, 3, 9, 5, 5, 3, 59, 7, 61, 3, 5, 5, 9, 3, 67, 5, 5, 3, 71, 9, 73, 3, 5, 5, 13, 3, 79, 5, 5, 3, 83, 7, 9, 3, 5, 5, 89, 3, 13, 5, 5, 3

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OFFSET

1,2

COMMENTS

n mod a(n) = 0 or GCD(n,a(n)) = 1;

a(n) = n iff n=1 or n=4 or n is prime; a(A046022(n))=A046022(n);

a(p^2) = 2*p - 1 for odd primes p.

LINKS

R. Zumkeller, Table of n, a(n) for n = 1..10000

CROSSREFS

Cf. A027750, A038566, A076274.

Sequence in context: A223491 A346088 A275823 * A134198 A060653 A274690

Adjacent sequences: A141292 A141293 A141294 * A141296 A141297 A141298

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jun 23 2008

STATUS

approved