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

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, 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, 2, 3, 3, 3, 2, 2, 3, 3, 3, 3, 4, 4, 2, 1, 2, 2, 2, 2

Offset: 0

Author

Reinhard Zumkeller, May 08 2011

Keywords

• nonn
• base

Comments

For n > 0: a(A000290(n)) = 1; for n > 1: a(A002522(n)) = 2;

a(n) <= A000196(n).

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A190311, A053610.

Programs

Haskell

a190321 n = g n $ reverse $ takeWhile (<= n) $ tail a000290_list where
  g _ []                 = 0
  g m (x:xs) | x > m     = g m xs
             | otherwise = signum m' + g r xs where (m',r) = divMod m x