A136998 Numbers k such that k and k^2 use only the digits 1, 2, 4, 7 and 9.

1, 2, 7, 11, 12, 21, 27, 171, 212, 421, 479, 2729, 2777, 4911, 4912, 11171, 21729, 44127, 49777, 112912, 119127, 221911, 279271, 471479, 477412, 492921, 497212, 499479, 974229, 1194771, 1214171, 2174229, 2219171, 4412729, 4471479, 4721729, 4794911, 4919271, 4927421, 4929277, 4994777, 4997212, 4997271, 4997277, 4997777, 9997212, 12129271

Offset

1,2

Comments

Generated with DrScheme.

Links

Jonathan Wellons, Table of n, a(n) for n = 1..540

J. Wellons, Tables of Shared Digits [archived]

Example

492421742492421^2 = 242479172479272177477242441241.

Crossrefs

Sequence in context: A359167 A299242 A184792 * A136734 A113544 A045173

Adjacent sequences: A136995 A136996 A136997 * A136999 A137000 A137001

Keyword

base,nonn,changed

Author

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Status

approved