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A059960
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Smaller term of a pair of twin primes such that prime factors of their average are only 2 and 3.
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17
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5, 11, 17, 71, 107, 191, 431, 1151, 2591, 139967, 472391, 786431, 995327, 57395627, 63700991, 169869311, 4076863487, 10871635967, 2348273369087, 56358560858111, 79164837199871, 84537841287167, 150289495621631
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Primes p(k) such that the number of distinct prime divisors of all composite numbers between p(k) and p(k+1) is 2. - Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 26 2002
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LINKS
| T. D. Noe, Table of n, a(n) for n = 1..49 (terms < 10^300)
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FORMULA
| Primes p such that p+1 = (2^u)*(3^w)
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EXAMPLE
| a(11)+1 = 2*2*2*3*3*3*3*3*3*3*3*3*3 = 472392.
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MATHEMATICA
| nn=10^15; Sort[Reap[Do[n=2^i 3^j; If[n<=nn && PrimeQ[n-1] && PrimeQ[n+1], Sow[n-1]], {i, Log[2, nn]}, {j, Log[3, nn]}]][[2, 1]]]
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CROSSREFS
| Cf. A014574, A002822, A033845, A058383, A059961.
Cf. A052297, A075581, A075580, A075583, A075584, A075585, A075586, A075587, A075588, A075589.
Apart from initial terms, same as A078883.
Sequence in context: A050836 A058019 A075582 * A185365 A118122 A166039
Adjacent sequences: A059957 A059958 A059959 * A059961 A059962 A059963
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Mar 02 2001
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