A053967 Squares composed of digits {4,8,9}.

4, 9, 49, 484, 4489, 44944, 444889, 499849, 44448889, 449948944, 4444488889, 444444888889, 949488489889, 9988488448849, 44444448888889, 99488994489889, 449448988844944, 4444444488888889, 44484944448898849, 444444444888888889, 948449484498898944, 44444444448888888889

Offset

1,1

Comments

Includes all numbers of the form (2*(10^k-1)/3 + 1)^2 for k >= 1. - Andrew Howroyd, Oct 18 2024

Links

Zhao Hui Du, Table of n, a(n) for n = 1..45

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

Formula

a(n) = A053966(n)^2. - Andrew Howroyd, Oct 18 2024

Mathematica

Select[Flatten[Table[FromDigits/@Tuples[{4, 8, 9}, n], {n, 10}]], IntegerQ[ Sqrt[#]]&] (* The program generates the first 11 terms of the sequence. To generate all of the shown terms, increase the "n" constant from 10 to 18 but the program will take a long time to run. *) (* Harvey P. Dale, Jan 11 2019 *)

Crossrefs

Cf. A053966.

Sequence in context: A110481 A030088 A081069 * A028945 A086541 A053965

Adjacent sequences: A053964 A053965 A053966 * A053968 A053969 A053970

Keyword

nonn,base

Author

Patrick De Geest, Mar 15 2000

Status

approved