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A065022
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The sums of the composite numbers up to n-1 and n+1 are twin primes.
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0
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4, 8, 290, 340, 352, 412, 489, 610, 774, 785, 1227, 1295, 1306, 1795, 1853, 1918, 1945, 2014, 2266, 2502, 2885, 3063, 3133, 3178, 3265, 3482, 3486, 3680, 3760, 3843, 3973, 3995, 4124, 4794, 5677, 5769, 5965, 6123, 7555, 7653, 7696, 7765, 7786, 8023
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| 4+6+8 = 18 and 18 +/-1 are twin primes.
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MATHEMATICA
| Composite[n_Integer] := (k = n + PrimePi[n] + 1; While[k - PrimePi[k] - 1 != n, k++ ]; k); s = 0; Do[m = Composite[n]; s = s + m; If[ PrimeQ[s - 1] && PrimeQ[s + 1], Print[m]], {n, 1, 10^4} ]
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CROSSREFS
| Sequence in context: A085631 A074073 A090653 * A012994 A136386 A177860
Adjacent sequences: A065019 A065020 A065021 * A065023 A065024 A065025
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 01 2001
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