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A339182
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Primes p such that q = p mod A001414(p-1) = p mod A001414(p+1) is prime.
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2
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251, 991, 1429, 1567, 1597, 1741, 2243, 3739, 4003, 4049, 4129, 4271, 4513, 5407, 6673, 6733, 9539, 9631, 10639, 14627, 14947, 16561, 18617, 18749, 18797, 19081, 20551, 24851, 28729, 31151, 37571, 42641, 49529, 50047, 54751, 56897, 59513, 65563, 73751, 75683, 77743, 89783, 91807, 96799, 104537
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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a(4) = 1567 is in the sequence because 1567 is prime, A001414(1566) = 2+3+3+3+29 = 40, A001414(1568) = 2+2+2+2+2+7+7=24, 1567 mod 40 = 1567 mod 24 = 7 is prime.
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MAPLE
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spf:= n -> add(t[1]*t[2], t=ifactors(n)[2]):
filter:= proc(p) local v;
if not isprime(p) then return false fi;
v:= p mod spf(p-1);
isprime(v) and p mod spf(p+1) = v
end proc:
select(filter, [seq(i, i=3..10^5, 2)]);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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