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A142340
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Primes of the form (p(n)-2*n)/7, where p(n)=n-th prime.
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1
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3, 5, 7, 7, 23, 23, 43, 67, 71, 73, 127, 127, 151, 163, 173, 181, 199, 199, 229, 239, 257, 271, 293, 353, 383, 419, 419, 457, 463, 479, 487, 523, 571, 599, 601, 617, 631, 643, 643, 673, 733, 739, 739, 761, 821, 827, 827, 863, 881, 881, 887, 907, 937, 967, 1033
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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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If n=16, then (p(16)-2*16)/7=(53-32)/7=3=a(1).
If n=22, then (p(22)-2*22)/7=(79-44)/7=5=a(2).
If n=26, then (p(26)-2*26)/7=(101-52)/7=7=a(3).
If n=27, then (p(27)-2*27)/7=(103-54)/7=7=a(4).
If n=60, then (p(60)-2*60)/7=(281-120)/7=23=a(5), etc.
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MAPLE
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for n from 1 to 3000 do p := (ithprime(n)-2*n)/7 ; if type(p, 'integer') then if isprime(p) then printf("%d, ", p) ; end if; end if; end do: # R. J. Mathar, Apr 28 2010
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MATHEMATICA
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Select[Table[(Prime[n]-2n)/7, {n, 2000}], PrimeQ] (* Harvey P. Dale, Sep 19 2020 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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