A137416 Smallest nontrivial square (i.e., not of the form 10^2k, k > 0) with exactly n identical adjacent digits.

1, 144, 1444, 1666681, 111112681, 3333330225, 132922222225, 1433333333961, 2582708888888881, 28777777777780164, 88888888888905609, 55555555555566005625, 2222222222222640225, 4777777777777776827176356

Offset

1,2

Comments

Since a(13) < a(12), a(13) is actually the smallest nontrivial square with at least 12 identical adjacent digits. a(12) is the smallest containing 12, but not more than 12, identical adjacent digits. - Jon E. Schoenfield, May 16 2010

Links

Table of n, a(n) for n=1..14.

Example

a(3) = 1444 because it has 3 adjacent 4's, and no square less than 1444 has 3 adjacent digits which are the same.

Crossrefs

See A169859 for another version.

Sequence in context: A023096 A223435 A169859 * A109117 A209205 A223594

Adjacent sequences: A137413 A137414 A137415 * A137417 A137418 A137419

Keyword

nonn,base,more

Author

Randy L. Ekl, Apr 15 2008

Extensions

a(11) from Donovan Johnson, May 08 2010

a(12)-a(14) from Jon E. Schoenfield, May 16 2010

Status

approved