A035123 Roots of 'non-palindromic squares remaining square when written backwards'.

12, 13, 21, 31, 33, 99, 102, 103, 112, 113, 122, 201, 211, 221, 301, 311, 1002, 1003, 1011, 1012, 1013, 1021, 1022, 1031, 1101, 1102, 1103, 1112, 1113, 1121, 1122, 1201, 1202, 1211, 1212, 1301, 2001, 2011, 2012, 2021, 2022, 2101, 2102, 2111, 2121

Offset

1,1

Comments

Those with trailing zeros are excluded.

Union of ordered entries of A106323 and A106324. - Lekraj Beedassy, May 02 2005

Links

Jon E. Schoenfield, Table of n, a(n) for n = 1..8448 (first 798 terms from Seiichi Manyama; all terms < 10^10)

Patrick De Geest, Palindromic Squares in bases 2 to 17

Eric Weisstein's World of Mathematics, Square Number

Example

1212^2 = 1468944 -> 4498641 = 2121^2.

Mathematica

r[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Select[Range[2200], Mod[#, 10] != 0 && IntegerQ[Sqrt[r[#^2]]] && r[#^2] != #^2 &] (* Jean-François Alcover, Mar 08 2011 *)

Crossrefs

Cf. A035090, A035125.

Sequence in context: A225102 A057488 A105733 * A140212 A123132 A050840

Adjacent sequences: A035120 A035121 A035122 * A035124 A035125 A035126

Keyword

nonn,base

Author

Patrick De Geest, Nov 15 1998

Status

approved