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!)
A254072 Numbers n such that the decimal expansions of both n and n^2 have 4 as the digit with the smallest value and 9 as the digit with the largest value. 3
974, 9476, 9874, 69684, 94588, 94657, 94788, 94867, 97457, 99476, 99784, 669684, 677974, 697764, 699684, 699764, 699784, 746957, 869457, 945857, 946878, 946888, 947457, 947574, 947886, 947887, 947976, 948678, 974457, 974474, 984878, 998784, 6669684, 6696684 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
fQ[n_] := Block[{c = DigitCount@ n}, And[Plus @@ Take[c, {1, 3}] == 0, Last@ c == 0, c[[4]] > 0, c[[9]] > 0]]; Select[Range@ 1000000, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, May 05 2015 *)
PROG
(PARI) is(n) = vecmin(digits(n))==4 && vecmin(digits(n^2))==4 && vecmax(digits(n))==9 && vecmax(digits(n^2))==9
CROSSREFS
Sequence in context: A251837 A251838 A251845 * A253363 A253907 A233984
KEYWORD
nonn,base
AUTHOR
Felix Fröhlich, May 03 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 July 23 20:40 EDT 2024. Contains 374554 sequences. (Running on oeis4.)