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 A179055 #12 May 18 2019 18:04:44
%S A179055 1,4,9,11,22,33,44,55,66,77,88,99,243,324,432,567,675,756,1000,1010,
%T A179055 1020,1030,1040,1050,1060,1070,1080,1090,1111,1212,1313,1414,1515,
%U A179055 1616,1717,1818,1919,2000,2010,2020,2030,2040,2050,2060,2070,2080,2090,2121,2222,2323,2424
%N A179055 Numbers k such that the product of all numbers formed by cyclically permuting digits of k is a square.
%e A179055 756 is in the sequence because 756 * 567 * 675 = 289340100 = 17010^2.
%p A179055 with(numtheory):for n from 1 to 4000 do:pp:=1:n0:=n:l:=length(n0) :ind:=0:for
%p A179055 j from 1 to l do:s:=0:for m from 1 to l do:q:=n0:u:=irem(q, 10):v:=iquo(q, 10):n0:=v
%p A179055 :s:=s+ u*10^m:od:s:=floor(s-u*10^l+u):n0:=s: pp:=pp*s:od:x:=sqrt(pp) :y:=floor(x):if
%p A179055 x=y then printf(`%d, `, n): else fi :od:
%t A179055 cycDigitPerms[n_Integer, b_:10] := Module[{list = {n}, digits = IntegerDigits[n, b], len, counter, holder, next}, len = Length[digits]; counter = 1; While[counter < len, holder = digits[[-1]]; digits = Drop[digits, -1]; digits = Insert[digits, holder, 1]; list = Append[list, FromDigits[digits, b]]; counter++]; Return[list]]; Select[Range[2000], IntegerQ[Sqrt[Times@@cycDigitPerms[#]]] &] (* _Alonso del Arte_, Jan 04 2011 *)
%Y A179055 Cf. A061378 A062003 A061147.
%K A179055 nonn,base
%O A179055 1,2
%A A179055 _Michel Lagneau_, Jan 04 2011