|
| |
|
|
A085597
|
|
Numbers n such that n and n^3 use only odd digits.
|
|
1
|
|
|
|
1, 11, 15, 33, 39, 71, 91, 173, 175, 179, 335, 3337, 5597, 7353
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
Numbers n such that n^3 uses only odd digits are in A030099.
No additional terms up to 1 million. - Harvey P. Dale, May 15 2012
No additional terms up to 10^8. - Michel Marcus, Dec 03 2016
|
|
|
LINKS
|
Table of n, a(n) for n=1..14.
|
|
|
EXAMPLE
|
15 is a term because both 15 and 15^3=3375 use only odd digits.
|
|
|
MATHEMATICA
|
Select[Range[10000], And@@OddQ[Join[IntegerDigits[#], IntegerDigits[ #^3]]]&] (* Harvey P. Dale, May 15 2012 *)
|
|
|
PROG
|
(PARI) isoddd(n) = #select(x->((x%2) == 0), digits(n)) == 0;
isok(n) = isoddd(n) && isoddd(n^3); \\ Michel Marcus, Dec 03 2016
|
|
|
CROSSREFS
|
Cf. A030099.
Sequence in context: A009433 A275242 A030099 * A097512 A032490 A068483
Adjacent sequences: A085594 A085595 A085596 * A085598 A085599 A085600
|
|
|
KEYWORD
|
nonn,base,more
|
|
|
AUTHOR
|
Zak Seidov, Jul 06 2003
|
|
|
STATUS
|
approved
|
| |
|
|
