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A053669 Smallest prime not dividing n. +0
23
2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 7, 2, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2 (list; graph; listen)
OFFSET

1,1

COMMENT

Smallest prime coprime to n.

Smallest n >= 2 coprime to n.

a(#(p-1)) = a(A034386(p-1)) = p is the first appearance of prime p in sequence.

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

EXAMPLE

a(60) = 7, since all primes smaller than 7 divide 60 but 7 does not.

MATHEMATICA

Table[k := 1; While[Not[GCD[n, Prime[k]] == 1], k++ ]; Prime[k], {n, 1, 60}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 01 2006

CROSSREFS

Cf. A007978, A053670-A053674.

Sequence in context: A029208 A087242 A123556 this_sequence A112047 A112048 A060395

Adjacent sequences: A053666 A053667 A053668 this_sequence A053670 A053671 A053672

KEYWORD

nonn,nice,easy

AUTHOR

Henry Bottomley (se16(AT)btinternet.com), Feb 15 2000

EXTENSIONS

More terms from Andrew Gacek (andrew(AT)dgi.net), Feb 21 2000 and James A. Sellers (sellersj(AT)math.psu.edu), Feb 22 2000.

Entry revised by David W. Wilson, Nov 25 2006

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Last modified November 23 17:09 EST 2009. Contains 167438 sequences.


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