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A309152
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Numbers that can be written as the sum of two primes whose difference is also prime.
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6
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7, 8, 9, 12, 15, 21, 24, 33, 36, 45, 60, 63, 75, 84, 105, 111, 120, 141, 144, 153, 183, 195, 201, 204, 216, 231, 243, 273, 276, 285, 300, 315, 351, 360, 384, 396, 423, 435, 456, 465, 480, 525, 540, 564, 573, 603, 621, 624, 645, 663, 696, 813, 825, 831, 840
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OFFSET
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1,1
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COMMENTS
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Numbers k such that k = p + q where p < q and p, q, and q - p are all prime.
If k is even, then k is in A054735 with q - p = 2.
If k is odd, then k is in (A006512 + 2) with p = 2. (End)
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LINKS
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MAPLE
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P:= select(isprime, {seq(i, i=3..10000, 2)}):
T:= P intersect map(`+`, P, 2):
A1:= map(`+`, T, 2):
A2:= select(`<`, map(t -> 2*t-2, T), max(A1)):
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PROG
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(PARI) is(n) = my(x=n-1, y=1); while(x >= y, if(ispseudoprime(x) && ispseudoprime(y), if(ispseudoprime(x-y), return(1))); x--; y++); 0 \\ Felix Fröhlich, Jul 14 2019
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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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