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Search: id:A085305
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| A085305 |
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Numbers such that first reversing digits and after squaring equals the result of first-squaring and after-reversing. |
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+0
5
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| 1, 2, 3, 11, 12, 13, 21, 22, 31, 101, 102, 103, 111, 112, 113, 121, 122, 201, 202, 211, 212, 221, 301, 311, 1001, 1002, 1003, 1011, 1012, 1013, 1021, 1022, 1031, 1101, 1102, 1103, 1111, 1112, 1113, 1121, 1122, 1201, 1202, 1211, 1212, 1301, 2001, 2002, 2011
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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Solutions to rev[x^2]=rev[x]^2.
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EXAMPLE
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n=13 is here because 31^2=961=rev[169]=rev[13^2]=rev[rev[31]^2]
Number of solutions below 1000000 is 362.
Only digits {0,1,2,3} seem to arise.
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MATHEMATICA
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rt[x_] := tn[Reverse[IntegerDigits[x]]] Do[s=rt[n^2]; s1=rt[n]^2; If[Equal[s, s1]&&!Equal[Mod[n, 10], 0], Print[{n, s, rt[s1]}]], {n, 1, 1000000}]
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CROSSREFS
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Cf. A085306.
Sequence in context: A130803 A007932 A035122 this_sequence A116032 A116029 A060812
Adjacent sequences: A085302 A085303 A085304 this_sequence A085306 A085307 A085308
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KEYWORD
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base,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jun 27 2003
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