A239828 Cyclops numbers which are squares of cyclops numbers.

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

Author

Colin Barker, Mar 27 2014

Keywords

• nonn
• base

Comments

Subsequence of A160711.

Examples

			145106116 is in the sequence because 145106116 = 12046^2, and both 145106116 and 12046 are cyclops numbers.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A134808, A160711, A239827.

Programs

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

Formula

a(n) = A239827(n)^2.