A119644 - OEIS

A119644

a(n) = n-th prime from among those primes which are coprime to the n-th composite.

3, 7, 7, 11, 17, 19, 23, 29, 29, 37, 41, 43, 47, 53, 53, 61, 61, 71, 79, 73, 83, 89, 97, 101, 103, 107, 109, 127, 127, 131, 137, 139, 139, 151, 157, 163, 167, 173, 179, 181, 191, 197, 197, 199, 199, 223, 229, 229, 233, 241, 241, 251, 257, 263, 269, 277, 277, 277

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..58.

EXAMPLE

8 is the 3rd composite. 3,5,7,11,... is the sequence of primes which are coprime to 8. 7 is the 3rd term of these primes, so a(3) = 7.

PROG

(PARI) {m=60; c=1; for(n=1, m, c++; while(isprime(c), c++); q=2; k=n; while(k>0, p=q; if(gcd(p, c)==1, k--); q=nextprime(p+1)); print1(p, ", "))} - (Klaus Brockhaus, Aug 15 2006)

CROSSREFS

Sequence in context: A239126 A179873 A080457 * A109386 A024612 A227025

Adjacent sequences: A119641 A119642 A119643 * A119645 A119646 A119647

KEYWORD

nonn

AUTHOR

Leroy Quet, Aug 04 2006

EXTENSIONS

More terms from Klaus Brockhaus, Aug 15 2006

STATUS

approved