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 A067502 #18 Dec 24 2022 04:55:57 %S A067502 1,5,390625, %T A067502 24308653429145084793531500210078610314805672534067059113676236776522261070450716567124784465334818816238150740449697195799672044813632965087890625 %N A067502 Powers of 5 with digit sum also a power of 5. %C A067502 Next terms are 5^977, 5^1007, 5^4938, 5^24709, 5^24733, 5^24853. - _Sascha Kurz_, Mar 18 2002 %t A067502 Select[5^(Range[209]-1),IntegerQ[Log[5,Total[IntegerDigits[#]]]]&] (* _Stefano Spezia_, Dec 23 2022 *) %Y A067502 Cf. A066001, A067499, A067500, A067501. %K A067502 base,nonn %O A067502 1,2 %A A067502 _Amarnath Murthy_, Feb 11 2002