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Search: id:A141585
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| A141585 |
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Primes of the form (n-(p(n+2)-p(n))/(p(n+1)-p(n-1)))/2, where p(n)=n-th prime. |
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+0
1
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| 2, 3, 13, 29, 31, 37, 67, 71, 73, 139, 149, 197, 227, 229, 233, 241, 277, 331, 347, 431, 439, 467, 521, 547, 571, 587, 593, 743, 787, 797, 827, 859, 863, 877, 967, 1031, 1033, 1109, 1129, 1153, 1181, 1277, 1283, 1297, 1439, 1451, 1453, 1523, 1571, 1583, 1693
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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If n=5, then
(5-(p(5+2)-p(5))/(p(5+1)-p(5-1)))/2=(5-(17-11)/(13-7))/2=2=a(1).
If n=7, then
(7-(p(7+2)-p(7))/(p(7+1)-p(7-1)))/2=(7-(23-17)/(19-13))/2=3=a(2).
If n=48, then
(48-(p(48+2)-p(48))/(p(48+1)-p(48-1)))/2=(48-(233-227)/(229-223))/2=23=a(3).
If n=695, then
(695-(p(695+2)-p(695))/(p(695+1)-p(695-1)))/2=(695-(5237-5231)/(5233-5227))/2=347=a(4).
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CROSSREFS
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Cf. A000040.
Sequence in context: A087906 A029737 A105891 this_sequence A106867 A141861 A092175
Adjacent sequences: A141582 A141583 A141584 this_sequence A141586 A141587 A141588
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KEYWORD
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nonn
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Sep 10 2008
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EXTENSIONS
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Extended to 51 terms. First omission was 13 = (27 - (109 - 103) / (107 - 101)) / 2. a(3) was incorrect; the 48th prime is 223. Reikku Kulon (reikku(AT)gmail.com), Sep 16 2008
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