A066371 Smallest positive square that contains n consecutive internal 0's.

1, 1024, 60025, 1560001, 39000025, 1900000921, 460000002289, 2441400000004, 381470000000049, 64750000000005369, 259000000000021476, 800000000000150481, 20000000000003762025, 668913126000000000000025, 1100000000000000100085830916

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