OFFSET
1,2
COMMENTS
Subsequence of A239589.
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = sqrt(A239828(n)).
EXAMPLE
12046 is in the sequence because 12046^2 = 145106116, and both 12406 and 145106116 are cyclops numbers.
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, 100000, if(is_cyclops(n) && is_cyclops(n^2), s=concat(s, n))); s
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Colin Barker, Mar 27 2014
STATUS
approved