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A102617 Primes p(n) such that n is a second-order nonprime number. 12
2, 19, 29, 43, 47, 53, 71, 79, 89, 97, 103, 113, 131, 137, 149, 151, 163, 167, 173, 193, 199, 223, 227, 229, 233, 251, 257, 263, 271, 293, 307, 311, 317, 337, 347, 349, 359, 379, 383, 389, 397, 409, 421, 439, 443, 449, 457, 463, 479, 487, 491, 503, 523, 541 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The prime/nonprime compound sequence ABB. - N. J. A. Sloane, Apr 06 2016

LINKS

Table of n, a(n) for n=1..54.

EXAMPLE

Nonprime(4) = 8.

The 8th prime is 19, the second entry.

MAPLE

For Maple code for the prime/nonprime compound sequences (listed in cross-references) see A003622. - N. J. A. Sloane, Mar 30 2016

MATHEMATICA

nonPrime[n_Integer] := FixedPoint[n + PrimePi[ # ] &, n]; Prime /@ nonPrime /@ nonPrime /@ Range[54] (* Robert G. Wilson v, Feb 04 2005 *)

PROG

(PARI) \We perform nesting(s) with a loop. cips(n, m) = { local(x, y, z); for(x=1, n, z=x; for(y=1, m+1, z=composite(z); ); print1(prime(z)", ") ) } composite(n) = \ The n-th composite number. 1 is defined as a composite number. { local(c, x); c=1; x=0; while(c <= n, x++; if(!isprime(x), c++); ); return(x) }

CROSSREFS

Let A = primes A000040, B = nonprimes A018252. The 2-level compounds are AA = A006450, AB = A007821, BA = A078782, BB = A102615. The 3-level compounds AAA, AAB, ..., BBB are A038580, A049078, A270792, A102617, A270794, A270796, A102216.

Sequence in context: A186682 A031030 A083689 * A290163 A284496 A120276

Adjacent sequences:  A102614 A102615 A102616 * A102618 A102619 A102620

KEYWORD

nonn

AUTHOR

Cino Hilliard, Jan 31 2005

EXTENSIONS

Edited by Robert G. Wilson v, Feb 04 2005

STATUS

approved

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Last modified November 22 13:47 EST 2019. Contains 329393 sequences. (Running on oeis4.)