OFFSET
1,1
LINKS
Felix Fröhlich, Table of n, a(n) for n = 1..10000
MATHEMATICA
fQ[n_] := Block[{d = DigitCount@ n}, Last@ d == 0 && d[[1]] > 0 && d[[9]] > 0]; Select[Range@ 2000, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, Apr 20 2015 *)
PROG
(PARI) is(n) = vecmin(digits(n))==1 && vecmin(digits(n^2))==1 && vecmax(digits(n))==9 && vecmax(digits(n^2))==9
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Felix Fröhlich, Apr 20 2015
STATUS
approved