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 A257080 #15 Dec 23 2024 14:53:44 %S A257080 0,2,4,6,4,15,12,14,16,18,30,33,12,39,42,45,16,51,18,38,40,42,22,92, %T A257080 48,50,52,54,84,87,60,62,64,66,102,105,108,111,114,117,120,123,84,86, %U A257080 88,90,184,188,48,147,150,153,52,159,162,165,168,171,174,177,60,183,186,189,64,195,66,268,272,276,70,284,72 %N A257080 n multiplied by the least nonzero digit missing from its factorial base representation: a(n) = n * A257079(n). %H A257080 Antti Karttunen, <a href="/A257080/b257080.txt">Table of n, a(n) for n = 0..10080</a> %H A257080 Eric Angelini, et al, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2015-April/014728.html">"Multiply by the fantom digit", Discussion on Seqfan-list</a> %F A257080 a(n) = n * A257079(n). %o A257080 (Scheme) (define (A257080 n) (* n (A257079 n))) %Y A257080 A255411 gives the fixed points, positions where a(n) = n. %Y A257080 Cf. A257079, A257081 (number of iterations needed before a fixed point is reached). %K A257080 nonn,base,look %O A257080 0,2 %A A257080 _Antti Karttunen_, Apr 15 2015