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 A320723 #37 Feb 10 2019 17:15:37 %S A320723 30104309,100129033,109845884,451564392,622423768,916946759, %T A320723 6799389524,9336252149,19587821624,98891779017,255373745624, %U A320723 1499291015624,1532242466549,2023768276633,2636118566533,2644378346249,4324878052633,5560581801133,22242792374999 %N A320723 Reduced numbers with multiplicative persistence 9 in base 15. %C A320723 Let p_15(n) be the product of the digits of n in base 15. We can define an equivalence relation DP_15 on n by n DP_15 m if and only if p_15(n) = p_15(m); the naming DP_b for the equivalence relation stands for "digits product for representation in base b". A number n is called the class representative number of class n/DP_15 if and only if p_15(n) = p_15(m), m >= n; i.e., the smallest number of that class; it is also called the reduced number. %C A320723 For any multiplicative persistence, except the multiplicative persistence 2, the set of class representative numbers with that multiplicative persistence is conjectured to be finite. Each class representative number represents an infinite set of numbers with the same multiplicative persistence. %C A320723 If there exists a next reduced number m with multiplicative persistence 9, p(m) will be larger than 15^100, where p(m) is the product of the digits of m. %C A320723 a(1) = A320721(9). %H A320723 A.H.M. Smeets, <a href="/A320723/b320723.txt">Table of n, a(n) for n = 1..61</a> %e A320723 The number 30104309 represented in base 15, with A..E for 10..14 is 2999BDE. Other numbers with the same reduced number are for instance: 23399BDE,2999BD27, 12999BDE; or any number obtained by permutation of the digits of those numbers. %Y A320723 Cf. A320721, A320722. %K A320723 nonn,base %O A320723 1,1 %A A320723 _A.H.M. Smeets_, Oct 19 2018