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A179803 Numbers that contain the digital reverse of their square root 1
1, 25, 36, 729, 5476, 927369, 32752729, 37724164, 42562576, 97357689, 2825135104, 4325166756, 4860041796, 123715399824, 167904077121, 247679410276, 389724269841, 442094669604, 486004179600, 610118772201, 7473372660009 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..21.

FORMULA

a(n) = A115761(n)^2.

EXAMPLE

The square root of 729 is 27. 27's digital reverse is 72. 72 appears in 729.

MATHEMATICA

fQ[n_] := StringPosition[ IntegerString[n^2], StringReverse@ IntegerString@ n] != {}; k = 1; lst = {}; While[k < 3879404, If[ fQ@k, AppendTo[lst, k^2]]; k++ ]; lst (* Robert G. Wilson v, Jul 28 2010 *)

drsrQ[n_]:=Module[{s=Sqrt[n]}, MemberQ[Partition[Reverse[ IntegerDigits[ n]], IntegerLength[ s], 1], IntegerDigits[s]]]; Select[Range[ 28*10^5]^2, drsrQ] (* Harvey P. Dale, Dec 15 2015 *)

CROSSREFS

Cf. A115761.

Sequence in context: A030681 A167363 A035383 * A061863 A079270 A253025

Adjacent sequences:  A179800 A179801 A179802 * A179804 A179805 A179806

KEYWORD

nonn,base

AUTHOR

Dominick Cancilla, Jul 27 2010

EXTENSIONS

More terms from Robert G. Wilson v, Jul 28 2010

STATUS

approved

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Last modified December 5 15:11 EST 2019. Contains 329753 sequences. (Running on oeis4.)