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A190321 Number of nonzero digits when writing n in base where place values are squares, cf. A007961.

%I A190321 #8 Jul 13 2013 12:04:08
%S A190321 0,1,1,1,1,2,2,2,1,1,2,2,2,2,3,3,1,2,2,2,2,3,3,3,2,1,2,2,2,2,3,3,3,2,
%T A190321 2,3,1,2,2,2,2,3,3,3,2,2,3,3,3,1,2,2,2,2,3,3,3,2,2,3,3,3,3,4,1,2,2,2,
%U A190321 2,3,3,3,2,2,3,3,3,3,4,4,2,1,2,2,2,2
%N A190321 Number of nonzero digits when writing n in base where place values are squares, cf. A007961.
%C A190321 For n > 0: a(A000290(n)) = 1; for n > 1: a(A002522(n)) = 2;
%C A190321 a(n) <= A000196(n).
%H A190321 Reinhard Zumkeller, <a href="/A190321/b190321.txt">Table of n, a(n) for n = 0..10000</a>
%o A190321 (Haskell)
%o A190321 a190321 n = g n $ reverse $ takeWhile (<= n) $ tail a000290_list where
%o A190321   g _ []                 = 0
%o A190321   g m (x:xs) | x > m     = g m xs
%o A190321              | otherwise = signum m' + g r xs where (m',r) = divMod m x
%Y A190321 Cf. A190311, A053610.
%K A190321 nonn,base
%O A190321 0,6
%A A190321 _Reinhard Zumkeller_, May 08 2011