The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Subsequence of A160711. LINKS Giovanni Resta, Table of n, a(n) for n = 1..10000 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 Cf. A134808, A160711, A239827. Sequence in context: A285845 A160711 A129087 * A156942 A325311 A164518 Adjacent sequences:  A239825 A239826 A239827 * A239829 A239830 A239831 KEYWORD nonn,base AUTHOR Colin Barker, Mar 27 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 28 08:06 EST 2020. Contains 332321 sequences. (Running on oeis4.)