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Search: id:A133291
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| A133291 |
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a(n) = m such that t(n) +/- m are +-primes, where t(n) = n(n+1)/2. |
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+0
1
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| 4, 8, 11, 13, 22, 26, 31, 43, 52, 58, 61, 71, 72, 74
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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1-4=-3,1+4=5; 3-8=-5,3+8=11; 6-11=-5,6+11=17;
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MATHEMATICA
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a = 0; y = 0; For[i = 1, i < 15, a = a + i; Do[If[PrimeQ[a - k] && PrimeQ[a + k] && k > y, y = k; Break[]], {k, 250}]; Print[a, ": ", a - y, ", ", y, ", ", a + y]; i++ ]
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CROSSREFS
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Sequence in context: A068798 A038162 A026999 this_sequence A072518 A073302 A047346
Adjacent sequences: A133288 A133289 A133290 this_sequence A133292 A133293 A133294
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KEYWORD
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nonn
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AUTHOR
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Vladimir Joseph Orlovsky (4vladimir(AT)gmail.com), Oct 17 2007
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