This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A204575 #5 Mar 30 2012 17:23:05 %S A204575 0,1,1001,100100001,10011001001001,1010001010010000001, %T A204575 101011001001001011001001,10110111001100110101000100001, %U A204575 1100001001111011011000010110001001,110011100111010101001010101001000000001 %N A204575 Squares such that [a(n)/2] is again a square (A055792), written in binary. %Y A204575 See also A031149=sqrt(A023110) (base 10), A204502=sqrt(A204503) (base 9), A204514=sqrt(A055872) (base 8), A204516=sqrt(A055859) (base 7), A204518=sqrt(A055851) (base 6), A204520=sqrt(A055812) (base 5), A004275=sqrt(A055808) (base 4), A001075=sqrt(A055793) (base 3), A001541=sqrt(A055792) (base 2). %K A204575 nonn,base %O A204575 1,3 %A A204575 _M. F. Hasler_, Jan 16 2012