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 A087907 Numbers n such that n*359# +-1 are twin primes, where 359# = 72nd primorial (A002110(72)). 0
 983, 1211, 1345, 2134, 2260, 4981, 8102, 9788, 10074, 10406, 10923, 11254, 11821, 11896, 12122, 14428, 14809, 15568, 15758, 17909, 23197, 24634, 25646, 26236, 26781, 27850, 28648, 30739, 31515, 31671, 37875, 40653, 41621, 43983, 44773 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For the i-th primorial there are roughly floor(16*log(2*P(i))) solutions j for the Diophantine equation: j*P(i)# -1 and +1 are prime twins with i >= 7 For i=72, P(i)=359, 115 j values, int(16*log(2*359))=105 For i=26, P(i)=101, 67 j values, int(16*log(2*101))=73 For i=38, P(i)=163, 107 j values, int(16*log(2*163))=81 For i=50, P(i)=229, 102 j values, int(16*log(2*229))=98 LINKS Table of n, a(n) for n=1..35. EXAMPLE 134464*359# -1 and +1 are twin primes, 134464 is the 115th j value and the last of this sequence MATHEMATICA With[{pmrl=Fold[Times, Prime[Range[72]]]}, Select[Range[45000], AllTrue[ pmrl*#+{1, -1}, PrimeQ]&]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 29 2017 *) CROSSREFS P# = A002110. Sequence in context: A251839 A122472 A252402 * A351665 A182574 A096701 Adjacent sequences: A087904 A087905 A087906 * A087908 A087909 A087910 KEYWORD nonn AUTHOR Pierre CAMI, Oct 15 2003 EXTENSIONS Needs to be edited in a similar manner to A087820. - N. J. A. Sloane STATUS approved

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Last modified September 21 08:32 EDT 2023. Contains 365499 sequences. (Running on oeis4.)