cp's OEIS Frontend

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.

A059405 Numbers that are the product of their digits raised to positive integer powers.

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%I A059405 #10 Jan 10 2020 09:18:46
%S A059405 1,2,3,4,5,6,7,8,9,128,135,175,384,432,672,735,1296,1715,6144,6912,
%T A059405 13824,18432,23328,34992,82944,93312,131712,248832,442368,1492992,
%U A059405 2239488,2333772,2612736,3981312,4128768,4741632,9289728,12192768
%N A059405 Numbers that are the product of their digits raised to positive integer powers.
%C A059405 The second example suggests that a repeated digit must divide the number at least as many times as it occurs, i.e., "distinct [digits]" in the definition would give a different (super)set. What would be the additional terms? - _M. F. Hasler_, Jan 05 2020
%H A059405 Reinhard Zumkeller, <a href="/A059405/b059405.txt">Table of n, a(n) for n = 1..120</a>
%e A059405 a(17) = 1296 = (1)(2^2)(9)(6^2);
%e A059405 a(32) = 2333772 = (2)(3)(3)(3^3)(7)(7^3)(2).
%o A059405 (Haskell)
%o A059405 a059405 n = a059405_list !! (n-1)
%o A059405 a059405_list = filter f a238985_list where
%o A059405    f x = all (== 0) (map (mod x) digs) && g x digs where
%o A059405          g z []         = z == 1
%o A059405          g z ds'@(d:ds) = r == 0 && (h z' ds' || g z' ds)
%o A059405                           where (z', r) = divMod z d
%o A059405          h z []         = z == 1
%o A059405          h z ds'@(d:ds) = r == 0 && h z' ds' || g z ds
%o A059405                           where (z', r) = divMod z d
%o A059405          digs = map (read . return) $ filter (/= '1') $ show x
%o A059405 -- _Reinhard Zumkeller_, Apr 29 2015
%Y A059405 Subsequence of A238985.
%K A059405 base,nice,nonn
%O A059405 1,2
%A A059405 _Erich Friedman_, Jan 29 2001
%E A059405 More terms from _Erich Friedman_, Apr 01 2003
%E A059405 Offset changed by _Reinhard Zumkeller_, Apr 29 2015