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A066371
Smallest positive square that contains n consecutive internal 0's.
2
1, 1024, 60025, 1560001, 39000025, 1900000921, 460000002289, 2441400000004, 381470000000049, 64750000000005369, 259000000000021476, 800000000000150481, 20000000000003762025, 668913126000000000000025, 1100000000000000100085830916
OFFSET
0,2
EXAMPLE
a(2)= 60025 since 60025 is square and contains 2 consecutive internal 0's.
MATHEMATICA
Do[k = Floor[10^(n/2)]; While[a = Flatten[ Position[ IntegerDigits[k^2], 0]]; Mod[k, 10] == 0 || Length[a] < n || Last[a] - First[a] + 1 != n, k++ ]; Print[k^2], {n, 0, 8} ]
CROSSREFS
Square roots are in A066392.
Sequence in context: A321819 A231309 A134847 * A236216 A264002 A016961
KEYWORD
base,nonn
AUTHOR
Erich Friedman, Dec 22 2001
EXTENSIONS
More terms from Robert G. Wilson v, Dec 23 2001
a(9)-a(14) from Lars Blomberg, Apr 29 2013
STATUS
approved