|
| |
|
|
A054039
|
|
a(n)^2 is the least square to contain n different decimal digits.
|
|
9
| | |
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| It turns out that "...at least n..." and "...exactly n..." yield the same (and thus strictly increasing) sequence. - M. F. Hasler, Feb 02 2009
|
|
|
EXAMPLE
| 13^2=169 is the first square to contain exactly 3 different digits; 322^2=103684 is the first square to contain exactly 6 different digits.
|
|
|
PROG
| (PARI) A054039(n, k=0) = { while( #Set(Vec(Str(k^2)))<n, k++); k } /* If "exactly n" would correspond to a different sequence, this would yield some term twice in a row. The optional 2nd arg can be used to find further terms with a given # of distinct digits. - M. F. Hasler, Feb 02 2009 */
|
|
|
CROSSREFS
| Cf. A016069, A054031, A054032, A054033, A054034, A054035, A054036, A054037, A054038.
Sequence in context: A060099 A173277 A036420 * A124669 A036894 A176361
Adjacent sequences: A054036 A054037 A054038 * A054040 A054041 A054042
|
|
|
KEYWORD
| nonn,fini,full,base,easy
|
|
|
AUTHOR
| Asher Auel (asher.auel(AT)reed.edu) Feb 28 2000
|
|
|
EXTENSIONS
| Minor rewording, added comment, keywords "easy,full" and PARI code M. F. Hasler (www.univ-ag.fr/~mhasler), Feb 02 2009
|
| |
|
|
