A030099 Numbers k such that k^3 has only odd digits.

1, 11, 15, 33, 39, 71, 91, 173, 175, 179, 211, 259, 335, 3337, 4631, 5597, 7353, 12415, 21353, 22893, 25799, 69491, 110011, 124975, 199831, 227353, 237151, 462815, 492415, 708415, 1100033, 2393695, 2620611, 5088493, 5828415, 7204417, 8320335, 11164415, 11689633

Offset

1,2

Links

Giovanni Resta, Table of n, a(n) for n = 1..563 (terms < 10^19, first 75 terms from Reinhard Zumkeller, terms 76..151 from Max Alekseyev)

Mathematica

fQ[n_] := Union@ OddQ@ IntegerDigits[n^3] == {True}; Select[2 Range[3*10^6] - 1, fQ] (* Robert G. Wilson v, Aug 13 2011 *)
Select[Range[12*10^6], AllTrue[IntegerDigits[#^3], OddQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 14 2015 *)

Prog

(Haskell)
import Data.List (intersect)
a030099 n = a030099_list !! (n-1)
a030099_list = filter (null . (intersect "86420") . show . (^ 3)) [1, 3..]
-- Reinhard Zumkeller, Aug 13 2011

Crossrefs

Cf. A000578, A030100, A034376, A052004.

Sequence in context: A009407 A009433 A275242 * A085597 A316643 A373610

Adjacent sequences: A030096 A030097 A030098 * A030100 A030101 A030102

Keyword

nonn,base,nice

Author

Patrick De Geest

Status

approved