

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
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OFFSET

0,2


LINKS

Table of n, a(n) for n=0..14.


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
Adjacent sequences: A066368 A066369 A066370 * A066372 A066373 A066374


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



