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 A239477 #6 Mar 20 2014 07:52:39 %S A239477 0,10,28,289,2488888888888888999999999 %N A239477 Smallest number with additive and multiplicative persistence equal to n. %C A239477 The corresponding smallest primes are 2, 11, 29, 487 and 2488888888888898999989999. %e A239477 a(3) = 289 because 289 is the smallest number with additive persistence 3, 289 -> 19 -> 10 -> 1 and multiplicative persistence 3, 289 -> 144 -> 16 -> 6. %Y A239477 Cf. A031346, A003001, A031286, A006050, A239427. %K A239477 nonn,base %O A239477 0,2 %A A239477 _Giovanni Resta_, Mar 20 2014