OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..4000
EXAMPLE
138 is in the sequence because 138^2 = 19044, which is a cyclops number.
PROG
(PARI)
is_cyclops(k) = {
if(k==0, return(1));
my(d=digits(k), j);
if(#d%2==0 || d[#d\2+1]!=0, return(0));
for(j=1, #d\2, if(d[j]==0, return(0)));
for(j=#d\2+2, #d, if(d[j]==0, return(0)));
return(1)}
s=[]; for(n=0, 2000, if(is_cyclops(n^2), s=concat(s, n))); s
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Colin Barker, Mar 24 2014
STATUS
approved