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

Author

Patrick De Geest, Nov 15 1998

Keywords

• nonn
• base

Comments

Those with trailing zeros are excluded.

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

Examples

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

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

Crossrefs

Cf. A035090, A035125.

Programs

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 *)