A046872 - OEIS

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A046872

F-primes.

7, 47, 191, 239, 307, 463, 499, 701, 743, 787, 853, 1087, 1123, 1301, 1487, 1553, 1567, 1823, 2309, 2621, 2843, 2903, 3083, 3203, 3319, 3323, 3359, 3373, 3541, 3583, 3557, 3617, 3659, 3671, 3727, 3769, 3863, 3947, 4217, 4327, 4373, 4391

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OFFSET

1,1

COMMENTS

Call the numbers in A008849 F-numbers; then a prime p is called an F-prime if there exists a squarefree F-number q_1*q_2*...*q_r*p with q_1 < q_2 < ... < q_r < p in which the q_i's are primes but not F-primes.

REFERENCES

I. Kaplansky, The challenges of Fermat, Wallis and Ozanam (and several related challenges): I. Fermat's first challenge, Preprint, 2002.

LINKS

Table of n, a(n) for n=1..42.

CROSSREFS

Cf. A008849.

Sequence in context: A158713 A142185 A158914 * A167860 A152988 A336789

Adjacent sequences: A046869 A046870 A046871 * A046873 A046874 A046875

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane, Oct 05 2002

STATUS

approved