

A163080


Primes p such that p$  1 is also prime. Here '$' denotes the swinging factorial function (A056040).


3



3, 5, 7, 13, 41, 47, 83, 137, 151, 229, 317, 389, 1063
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OFFSET

1,1


COMMENTS

a(n) are the primes in A163078.


REFERENCES

Peter Luschny, "Divide, swing and conquer the factorial and the lcm{1,2,...,n}", preprint, April 2008.


LINKS

Table of n, a(n) for n=1..13.
Peter Luschny, Swinging Primes.


EXAMPLE

3 is prime and 3$  1 = 5 is prime, so 3 is in the sequence.


MAPLE

a := proc(n) select(isprime, select(k > isprime(A056040(k)1), [$0..n])) end:


MATHEMATICA

sf[n_] := n!/Quotient[n, 2]!^2; Select[Prime /@ Range[200], PrimeQ[sf[#]  1] &] (* JeanFrançois Alcover, Jun 28 2013 *)


CROSSREFS

Cf. A163079, A163078, A103317.
Sequence in context: A075557 A244452 A057187 * A141414 A236464 A064268
Adjacent sequences: A163077 A163078 A163079 * A163081 A163082 A163083


KEYWORD

nonn


AUTHOR

Peter Luschny, Jul 21 2009


STATUS

approved



