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Search: id:A067465
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| A067465 |
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Numbers n such that sigma(n^2+1) is a perfect square. |
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+0
1
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| 0, 13, 64, 67, 189, 344, 900, 2499, 3028, 4253, 5257, 6277, 9075, 11516, 12544, 18739, 18925, 47018, 49011, 62355, 72981, 112061, 125011, 125653, 152765, 167820, 168317, 174724, 179040, 225492, 240597, 251568, 261163, 302128, 302812, 345283
(list; graph; listen)
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OFFSET
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1,2
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PROGRAM
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(PARI) for(n=0, 500000, if(issquare(sigma(n^2+1)), print1(n, ", ")))
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CROSSREFS
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Adjacent sequences: A067462 A067463 A067464 this_sequence A067466 A067467 A067468
Sequence in context: A031074 A051878 A092653 this_sequence A166605 A054477 A010820
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KEYWORD
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easy,nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 23 2002
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EXTENSIONS
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More terms from Rick L. Shepherd (rshepherd2(AT)hotmail.com), Apr 16 2002
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