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Search: id:A075712
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| A075712 |
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Rearrangement of primes into Germain groups. |
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1
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| 2, 5, 11, 23, 47, 3, 7, 13, 17, 19, 29, 59, 31, 37, 41, 83, 167, 43, 53, 107, 61, 67, 71, 73, 79, 89, 179, 359, 719, 1439, 2879, 97, 101, 103, 109, 113, 227, 127, 131, 263, 137, 139
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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In each group p(i+1) = 2*p(i)+1: {2, 5, 11, 23, 47}, {3, 7}, {13}, {17}, {19}, {29, 59}, {31}, {37}, {41, 83, 167}, {43},{53, 107}, {61}, {67}, {71}, {73}, {79}, {89, 179, 359, 719, 1439, 2879}, {97}, {101}, {103}, {109}, {113, 227}, {127}, {131, 263}, {137}, {139}. By the way, it is a question whether the group with one prime is a Germain group. What i call here Germain group is also known as Cunningham chain of the first kind, A059452, A059453, A059455, A059456, A053176.
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EXAMPLE
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First three Germain groups are: {2, 5, 11, 23, 47}, {3, 7}, {13}.
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CROSSREFS
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Cf. A005384, A059452, A059453, A059455, A059456, A053176.
Sequence in context: A147878 A140992 A093053 this_sequence A000100 A083005 A133489
Adjacent sequences: A075709 A075710 A075711 this_sequence A075713 A075714 A075715
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KEYWORD
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nonn,tabf
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Oct 03 2002
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