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A345214
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Primes p such that the sum of 2^k for k such that 2^k < p and p+2^k is prime is greater than p.
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2
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67, 73, 149, 641, 659, 1039, 1063, 1087, 1117, 2081, 2111, 2153, 2459, 2549, 4201, 4273, 4327, 4447, 4567, 4903, 5077, 5107, 8219, 8501, 8537, 8819, 8861, 8999, 9011, 9209, 9239, 10061, 10331, 16417, 16447, 16573, 16603, 16927, 16963, 16993, 17389, 17467, 17977, 18757, 19777, 20143, 20563, 21487
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(4) = 641 is a member because 641+2 = 643, 641+32 = 673, 641+128 = 769 and 641+512=1153 are prime and 2+32+128+512 = 674 > 641.
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MAPLE
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filter:= proc(p) local i;
convert(select(t -> isprime(p+t), [seq(2^i, i=1..ilog2(p))]), `+`) > p
end proc:
select(filter, [seq(ithprime(i), i=1..10000)]);
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MATHEMATICA
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filterQ[p_] := Total@Select[2^Range[Length[IntegerDigits[p, 2]]-1], PrimeQ[p+#]&] > p;
Select[Prime[Range[10000]], filterQ] (* _Jean-François Alcover_, Jun 11 2021 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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_J. M. Bergot_ and _Robert Israel_, Jun 10 2021
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STATUS
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approved
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