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A053909
Squares composed of digits {1,6,8}.
3
1, 16, 81, 1681, 11881, 1666681, 818188816, 6168688681, 6661661161, 611686666816, 1111166866161, 11168168618161, 18886681666161, 666868181611681, 866686868686116, 16668111611611681, 668881818661618116, 866881188818186116, 6181118111681186116, 6811866166886681616
OFFSET
1,2
FORMULA
a(n) = A053908(n)^2. - Andrew Howroyd, Oct 18 2024
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{1, 6, 8}, {n}], IntegerQ[Sqrt[#]]&], {n, 10}]] (* Harvey P. Dale, Apr 22 2011 *)
CROSSREFS
Cf. A053908.
Sequence in context: A046453 A030514 A056571 * A151502 A030693 A308249
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Mar 15 2000
EXTENSIONS
a(18) onwards using A053908 added by Andrew Howroyd, Oct 18 2024
STATUS
approved