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Search: id:A084755
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| A084755 |
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Let the sequence s_n be defined by s_n(1) = n+1, and for k > 1, s_n(k) = k*s_n(k-1)+1. Then a(n) is the first prime in the sequence s_n. |
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| 2, 3, 113, 5, 13, 7, 17, 19, 257, 11, 9157, 13, 29, 31, 401, 17, 37, 19, 41, 43, 82440101, 23, 593, 617, 53, 1117601, 71222359652296203545715260298095475932840563720928496792310817334884559392569395657640073370291521
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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For n = 10r+1, a(n) >= s_n(6).
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EXAMPLE
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a(3) = 113: 3+1 = 4 is composite, 2*4+1 = 9 is composite, 3*9+1 = 28 is composite, 4*28+1 = 113 is prime.
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PROGRAM
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(Matlab) s = n + 1; k = 2; while (~isprime(s)) s = k*s + 1; k = k + 1; end a = s
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CROSSREFS
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Sequence in context: A109349 A114373 A117700 this_sequence A127819 A102697 A041813
Adjacent sequences: A084752 A084753 A084754 this_sequence A084756 A084757 A084758
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KEYWORD
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nonn,hard
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AUTHOR
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Amarnath Murthy and Meenakshi Srikanth (amarnath_murthy(AT)yahoo.com), Jun 16 2003
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EXTENSIONS
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Edited and extended by David Wasserman (wasserma(AT)spawar.navy.mil), Sep 09 2003
One more term from David Wasserman (wasserma(AT)spawar.navy.mil), Jan 05 2005
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