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A064152
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Erdos primes: primes p such that all p-k! for 1<=k!<p are composite.
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1
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2, 101, 211, 367, 409, 419, 461, 557, 673, 709, 769, 937, 967, 1009, 1201, 1259, 1709, 1831, 1889, 2141, 2221, 2309, 2351, 2411, 2437, 2539, 2647, 2837, 2879, 3011, 3019, 3041, 3049, 3079, 3163, 3217, 3221, 3359, 3389, 3499, 3593, 3671, 3709, 3833, 3851
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Numbers of Erdos primes <= 10^j for j=1,2,3,.... are 1, 1, 13, 95, 901, 7875, 71140, 646242, 5901409, ... For large j the asymptotic law seems to be #E(10^j)~(1/8)*(10^j/(j*ln(10))). If so the sequence is infinite.
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REFERENCES
| R. K. Guy, Unsolved Problems in Number Theory, A16.
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..7875
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PROG
| (PARI) { n=0; for (m=1, 10^9, p=prime(m); k=f=b=1; while ((f*=k) < p, if (isprime(p-f), b=0; break); k++); if (b, write("b064152.txt", n++, " ", p); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 09 2009]
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CROSSREFS
| Sequence in context: A195903 A042249 A157338 * A162353 A088272 A125819
Adjacent sequences: A064149 A064150 A064151 * A064153 A064154 A064155
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KEYWORD
| easy,nonn
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AUTHOR
| Felice Russo (frusso(AT)micron.com), Sep 13 2001
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