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 A378558 #4 Dec 04 2024 11:44:05 %S A378558 1,16,256,65536,16777216,1099511627776 %N A378558 Powers of 4 that do not include the digit 4. %C A378558 Any additional terms have an exponent of at least 10^5. %t A378558 Select[4^Range[0,100000],Not[MemberQ[IntegerDigits[#],4]]&] %Y A378558 Cf. A000302. %K A378558 nonn,base,hard,more %O A378558 1,2 %A A378558 _Erich Friedman_, Nov 30 2024