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A235708 Largest base in which n is pandigital.

%I A235708 #13 Feb 16 2025 08:33:21
%S A235708 1,2,1,2,2,2,1,2,2,2,3,2,2,2,3,2,2,2,3,2,3,2,2,2,2,2,2,2,3,2,1,3,3,3,
%T A235708 3,2,2,3,2,2,2,3,2,2,3,3,3,3,2,2,3,2,2,2,3,2,3,3,3,2,3,2,3,3,3,3,2,2,
%U A235708 3,2,2,2,3,2,4,2,2,4,2,2
%N A235708 Largest base in which n is pandigital.
%C A235708 The first occurrence of k in this sequence is given by A049363(k).
%H A235708 Reinhard Zumkeller, <a href="/A235708/b235708.txt">Table of n, a(n) for n = 1..10000</a>
%H A235708 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PandigitalNumber.html">Pandigital Number</a>
%H A235708 Wikipedia, <a href="http://en.wikipedia.org/wiki/Pandigital_number">Pandigital number</a>
%o A235708 (Haskell)
%o A235708 import Data.List (unfoldr, nub); import Data.Tuple (swap)
%o A235708 a235708 n = f n where
%o A235708    f 1 = 1
%o A235708    f b = if isPandigital b n then b else f (b - 1) where
%o A235708          isPandigital b = (== b) . length . nub . unfoldr
%o A235708            (\x -> if x == 0 then Nothing else Just $ swap $ divMod x b)
%o A235708 -- _Reinhard Zumkeller_, May 12 2014
%Y A235708 Cf. A049363.
%K A235708 nonn,base,nice
%O A235708 1,2
%A A235708 _Joonas Pohjonen_, May 02 2014