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A145848 Squares with an even number of digits, where the first half is a square and the second half is a nonzero square. 6
49, 1681, 144400, 225625, 256036, 324900, 576081, 24019801, 1299602500, 1587624025, 2371690000, 2496401296, 2528178961, 2924105625, 3132976729, 5198410000, 5616902916, 6350496100, 8122515625, 9985605184, 249001998001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

EXAMPLE

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

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}]]

CROSSREFS

Sequence in context: A088068 A140394 A008843 * A014942 A260856 A065785

Adjacent sequences:  A145845 A145846 A145847 * A145849 A145850 A145851

KEYWORD

nonn,base

AUTHOR

Tanya Khovanova, Oct 21 2008

EXTENSIONS

More terms from Jon E. Schoenfield, Nov 17 2008

Edited by Charles R Greathouse IV, Aug 02 2010

STATUS

approved

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Last modified June 17 13:12 EDT 2021. Contains 345080 sequences. (Running on oeis4.)