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A128921 Palindromes m such that reverse of m^2 is also a square. 4
0, 1, 2, 3, 11, 22, 33, 99, 101, 111, 121, 202, 212, 1001, 1111, 2002, 10001, 10101, 10201, 11011, 11111, 11211, 20002, 20102, 100001, 101101, 110011, 111111, 200002, 1000001, 1001001, 1002001, 1010101, 1011101, 1012101, 1100011, 1101011 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Most terms have a palindromic square; for the rare exceptions see A133901. - Klaus Brockhaus and Zak Seidov, Sep 29 2007

LINKS

Klaus Brockhaus, Table of n, a(n) for n = 1..360

EXAMPLE

33 and 99 are terms because 33^2=1089 => 9801=99^2 and 99^2=9801 => 1089=33^2.

MATHEMATICA

A128921=Select[Range[0, 100000], IntegerQ[Sqrt[FromDigits[Reverse[IntegerDigits[ #^2 ]]]]]&&FromDigits[Reverse[IntegerDigits[ # ]]]==#&]

CROSSREFS

Cf. A002113, A057135, A057136, A133901.

Sequence in context: A316187 A215952 A276375 * A118595 A229549 A229804

Adjacent sequences:  A128918 A128919 A128920 * A128922 A128923 A128924

KEYWORD

nonn,base,easy

AUTHOR

Zak Seidov, Mar 02 2005, definition corrected Sep 16 2007

EXTENSIONS

More terms from Klaus Brockhaus, Sep 23 2007

STATUS

approved

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Last modified May 6 21:35 EDT 2021. Contains 343597 sequences. (Running on oeis4.)