login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A256709 Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 9 as largest digit. 23
509, 890, 903, 905, 930, 950, 960, 970, 980, 990, 1039, 1091, 1095, 1097, 1390, 1709, 1903, 1905, 1930, 1970, 1980, 1990, 2049, 2093, 2095, 2097, 2190, 2509, 2809, 2903, 2905, 2907, 2930, 2970, 2990, 3009, 3049, 3079, 3090, 3092, 3095, 3097, 3098, 3099, 3209 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
fQ[n_] := Block[{c = DigitCount@ n}, And[c[[9]] > 0, c[[10]] > 0]]; Select[Range@ 3209, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, Apr 12 2015 *)
PROG
(PARI) is(n) = vecmin(digits(n))==0 && vecmin(digits(n^2))==0 && vecmax(digits(n))==9 && vecmax(digits(n^2))==9
CROSSREFS
Sequence in context: A198195 A142819 A183058 * A110025 A059763 A031421
KEYWORD
nonn,base
AUTHOR
Felix Fröhlich, Apr 08 2015
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)