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 A139410 #6 Jun 20 2022 09:50:23 %S A139410 4624,595968 %N A139410 Numbers n such that n = 4^d_1 + 4^d_2 + ... + 4^d_k where d_1d_2...d_k is the decimal expansion of n. %e A139410 595968 = 4^5 + 4^9 + 4^5 + 4^9 + 4^6 + 4^8. %t A139410 Select[Range[596000],Total[4^IntegerDigits[#]]==#&] (* _Harvey P. Dale_, May 21 2021 *) %K A139410 base,fini,full,nonn,bref %O A139410 1,1 %A A139410 _Farideh Firoozbakht_, May 11 2008