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 A196520 #11 Aug 13 2020 14:02:28 %S A196520 25,279936,31381059609,1125899906842624,1152921504606846976, %T A196520 4722366482869645213696,42391158275216203514294433201, %U A196520 324518553658426726783156020576256 %N A196520 Smallest Friedman number of order n. %C A196520 More terms from a=9 to a=12 are 22528399544939174411840147874772641, 147808829414345923316083210206383297601, 1427247692705959881058285969449495136382746624 and 91343852333181432387730302044767688728495783936. %H A196520 Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/0510.html">Problem of the Month May 2010</a> %F A196520 All numbers of this kind are perfect powers. %e A196520 Since 25 is the smallest Friedman number, it is the smallest Friedman number of order 1. %e A196520 279936 = 6^7 = (9 - 3)^(9 - 2), together using the digits of the number itself. Hence it is the smallest Friedman number of order 2. %e A196520 31381059609 = 9^11 = 9^(5+6) = 3^(30-8+0), together using the digits of the number itself. Hence it is the smallest Friedman number of order 3. %Y A196520 Cf. A036057 %K A196520 nonn,base %O A196520 1,1 %A A196520 _Kausthub Gudipati_, Oct 03 2011