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Search: id:A028985
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| A028985 |
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Nonsquare palindromes whose sum of divisors is odd. |
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+0
1
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| 2, 8, 242, 20402, 24642, 2004002, 2138312, 2468642, 85099058, 200040002, 204060402, 242484242, 291080192
(list; graph; listen)
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OFFSET
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0,1
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MATHEMATICA
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r[n_]:=FromDigits[Reverse[IntegerDigits[n, 10]], 10]; f[n_]:=n==r[n]&&IntegerQ[Sqrt[n+r[n]]]; Timing[lst={}; Do[If[f[n], AppendTo[lst, n]], {n, 1, 12!}]; lst] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 10 2009]
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CROSSREFS
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Sequence in context: A091503 A009588 A125264 this_sequence A067583 A120378 A012345
Adjacent sequences: A028982 A028983 A028984 this_sequence A028986 A028987 A028988
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KEYWORD
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nonn,base
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AUTHOR
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Patrick De Geest (pdg(AT)worldofnumbers.com)
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