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A270446
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Positive even numbers which are neither of the form p + 2^m + 1 nor of the form p + 2^m - 1 with p prime.
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1
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906, 3342, 3432, 4152, 4812, 4842, 5730, 7388, 7812, 8922, 10236, 10512, 11082, 11436, 12372, 12732, 13092, 14022, 14142, 14382, 14532, 15042, 15120, 16026, 16866, 17370, 18210, 18612, 18896, 18898, 20142, 20322, 20382, 20652, 21672, 24132, 24432, 24462
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OFFSET
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1,1
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COMMENTS
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Numbers whose distance to both nearest neighbor de Polignac numbers is 1.
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LINKS
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MAPLE
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filter:= proc(n) local m;
for m from 1 while n - 2^m > 0 do
if isprime(n - 2^m + 1) or isprime(n - 2^m-1) then return false fi
od;
true
end proc:
select(filter, [seq(i, i=4..30000, 2)]); # Robert Israel, Mar 22 2016
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PROG
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(Magma) lst:=[]; for n in [2..24462 by 2] do t:=Floor(Log(2, n)); c:=0; m:=0; while m le t do a:=n-2^m; if IsPrime(a+1) or IsPrime(a-1) then break; end if; c+:=1; m+:=1; end while; if c eq t+1 then Append(~lst, n); end if; end for; lst;
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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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