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A163079
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Primes p such that p$ + 1 is also prime. Here '$' denotes the swinging factorial function (A056040).
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4
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2, 3, 5, 31, 67, 139, 631, 9743, 16253, 17977, 27901, 37589
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| a(n) are the primes in A163077.
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REFERENCES
| Peter Luschny, "Divide, swing and conquer the factorial and the lcm{1,2,...,n}", preprint, April 2008.
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LINKS
| Peter Luschny, Swinging Primes.
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EXAMPLE
| 5 is prime and 5$+1=30+1=31 is prime, so 5 is in the sequence.
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MAPLE
| a := proc(n) select(isprime, select(k -> isprime(A056040(k)+1), [$0..n])) end:
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MATHEMATICA
| p = 2; lst = {}; While[p < 38000, a = f@p + 1; If[ PrimeQ@a, AppendTo[ lst, p]; Print@p]; p = NextPrime@p]; lst [From Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 08 2010]
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CROSSREFS
| Cf. A163077, A062363, A093804, A002981.
Cf. A056040. [From Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 09 2010]
Sequence in context: A186635 A106308 A036797 * A109845 A041019 A041977
Adjacent sequences: A163076 A163077 A163078 * A163080 A163081 A163082
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KEYWORD
| nonn
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AUTHOR
| Peter Luschny (peter(AT)luschny.de), Jul 21 2009
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EXTENSIONS
| a(8) - a(12) from Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 08 2010
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