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A239828
Cyclops numbers which are squares of cyclops numbers.
4
0, 11025, 42025, 93025, 121308196, 121506529, 121903681, 122301481, 144408289, 144504441, 145106116, 145805625, 145902241, 169702729, 169806961, 171505216, 196308121, 196504324, 197205849, 197908624, 198105625, 198302724, 256608361, 256704484, 257409936
OFFSET
1,2
COMMENTS
Subsequence of A160711.
LINKS
FORMULA
a(n) = A239827(n)^2.
EXAMPLE
145106116 is in the sequence because 145106116 = 12046^2, and both 145106116 and 12046 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^2))); s
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Colin Barker, Mar 27 2014
STATUS
approved