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A027856
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Dan numbers: numbers m of the form 2^j * 3^k such that m +- 1 are twin primes.
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12
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4, 6, 12, 18, 72, 108, 192, 432, 1152, 2592, 139968, 472392, 786432, 995328, 57395628, 63700992, 169869312, 4076863488, 10871635968, 2348273369088, 56358560858112, 79164837199872, 84537841287168, 150289495621632, 578415690713088, 1141260857376768
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OFFSET
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1,1
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COMMENTS
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Special twin prime averages (A014574).
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LINKS
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EXAMPLE
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a(14) = 243*4096 = 995328 and {995327, 995329} are twin primes.
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MATHEMATICA
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Select[#, Total@ Boole@ Map[PrimeQ, # + {-1, 1}] == 2 &] &@ Select[Range[10^7], PowerMod[6, #, #] == 0 &] (* Michael De Vlieger, Dec 31 2016 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Richard C. Schroeppel
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EXTENSIONS
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STATUS
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approved
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