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Search: id:A066741
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| A066741 |
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Pentagonal numbers whose reverse is a square. |
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+0
1
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| 0, 1, 925, 1426, 6112, 9801, 140301, 52244922262, 1445531162626, 5205252778462, 63253297234426, 42450593715870730
(list; graph; listen)
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OFFSET
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0,3
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EXAMPLE
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925 is pentagonal and 529 is square
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MATHEMATICA
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dtn[L_] := Fold[10#1+#2&, 0, L] A={0}; For[i=1, i>0, i++, t=i(3i-1)/2; r=dtn[Reverse[IntegerDigits[t]]]; If[IntegerQ[Sqrt[r]]&&Mod[t, 10]>0, AppendTo[A, t]; Print[A]]]
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CROSSREFS
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Sequence in context: A140906 A159701 A115696 this_sequence A147548 A116989 A152503
Adjacent sequences: A066738 A066739 A066740 this_sequence A066742 A066743 A066744
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KEYWORD
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base,more,nonn
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AUTHOR
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Erich Friedman (efriedma(AT)stetson.edu), Jan 16 2002
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EXTENSIONS
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a(11) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Apr 03 2008
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