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 A204573 #8 Sep 20 2014 15:07:56 %S A204573 0,0,0,1,4,16,121,400,1600,11881,39204,156816,1164241,3841600, %T A204573 15366400,114083761,376437604,1505750416,11179044361,36887043600, %U A204573 147548174400,1095432263641,3614553835204,14458215340816,107341182792481,354189388806400,1416757555225600 %N A204573 A204519(n)^2 = floor(A055851(n)/6): Squares which written in base 6, with some digit appended, yield another square. %C A204573 Base-6 analog of A202303. %F A204573 Conjecture: a(n) = 99*a(n-3)-99*a(n-6)+a(n-9) for n>10. - _Colin Barker_, Sep 20 2014 %F A204573 Empirical g.f.: -x^4*(x^6+16*x^5+4*x^4+22*x^3+16*x^2+4*x+1) / ((x-1)*(x^2+x+1)*(x^6-98*x^3+1)). - _Colin Barker_, Sep 20 2014 %o A204573 (PARI) b=6;for(n=0,1e7,issquare(n^2\b) & print1(n^2\b,",")) %Y A204573 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 A204573 nonn,base %O A204573 1,5 %A A204573 _M. F. Hasler_, Jan 16 2012