A053881 Squares composed of digits {1,2,4}.

1, 4, 121, 144, 441, 1444, 114244, 2214144, 11142244, 121242121, 421111441, 1111422244, 44424414441, 111114222244, 11111142222244, 214222214414224, 242441124211441, 411244411422244, 1111111422222244, 2111211444222241

Offset

1,2

Links

Zhao Hui Du, Table of n, a(n) for n = 1..54

Patrick De Geest, Squares containing at most three distinct digits, Index entries for related sequences

Formula

a(n) = A053880(n)^2.

Crossrefs

Cf. A053880.

Sequence in context: A286757 A239187 A062081 * A075114 A017186 A355751

Adjacent sequences: A053878 A053879 A053880 * A053882 A053883 A053884

Keyword

nonn,base

Author

Patrick De Geest, Mar 15 2000

Status

approved