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A086816
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Smaller member of a twin prime pair with a triangular sum.
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1
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17, 59, 137, 149, 1277, 1619, 2729, 4127, 6359, 11717, 13397, 17489, 20807, 23027, 28307, 29669, 51869, 61379, 69827, 73847, 78539, 92567, 97499, 115769, 138569, 166667, 176609, 193379, 200927, 258317, 304979, 430007, 500909, 518759, 536189
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OFFSET
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0,1
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COMMENTS
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It is easily shown that all terms end in 7 or 9.
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LINKS
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EXAMPLE
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59 is a term because it is the smaller member of the twin prime pair (59,61) and 59 + 61 = 120 = 15*(15+1)/2.
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MATHEMATICA
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Transpose[Select[Partition[Prime[Range[45000]], 2, 1], #[[2]]-#[[1]]==2 && IntegerQ[(Sqrt[1+8Total[#]]-1)/2]&]][[1]] (* Harvey P. Dale, Dec 15 2011 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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