A145848 Squares with an even number of digits, where the first half is a square and the second half is a nonzero square.

49, 1681, 144400, 225625, 256036, 324900, 576081, 24019801, 1299602500, 1587624025, 2371690000, 2496401296, 2528178961, 2924105625, 3132976729, 5198410000, 5616902916, 6350496100, 8122515625, 9985605184, 249001998001

Offset: 1

Author

Tanya Khovanova, Oct 21 2008

Keywords

• nonn
• base

Examples

			1681 is a square, where the first two digits form a square and the last two digits form a nonzero square.
		

Links

• Jon E. Schoenfield, Table of n, a(n) for n = 1..221
• Four Puzzles for the Price of One - from the 1997 USSR math olympiad

Programs

Mathematica

Flatten[Table[ Select[Flatten[ Table[FromDigits[ Join[IntegerDigits[i^2], PadLeft[IntegerDigits[j^2], n]]], {i, Floor[Sqrt[10^(n - 1)]], Floor[Sqrt[10^n - 1]]}, {j, Floor[Sqrt[10^n - 1]]}]], IntegerQ[Sqrt[ # ]] &], {n, 5}]]

Extensions

More terms from Jon E. Schoenfield, Nov 17 2008

Edited by Charles R Greathouse IV, Aug 02 2010