A119352 Smallest base b > 1 such that n in base b uses no digit b-1.

2, 3, 4, 3, 3, 4, 4, 5, 4, 3, 3, 5, 3, 3, 6, 5, 4, 4, 4, 6, 4, 4, 4, 7, 4, 4, 4, 3, 3, 7, 3, 3, 4, 4, 4, 5, 3, 3, 4, 3, 3, 4, 4, 5, 6, 6, 6, 9, 6, 6, 5, 5, 5, 5, 6, 5, 5, 5, 5, 7, 5, 5, 5, 5, 4, 4, 4, 5, 4, 4, 4, 7, 4, 4, 4, 5, 5, 5, 5, 6, 4, 3, 3, 5, 3, 3, 4, 5, 4, 4, 3, 3, 5, 3, 3, 9, 4, 4, 4, 6, 4, 4, 4, 7, 4

Offset

0,1

Links

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

Formula

7 is 111_2 (has 1), 21_3 (has 2), 13_4 (has 3), but 12_5 (no 4), so a(7)=5.

Prog

(Haskell)
a119352 n = f 2 n where
   f b x = g x where
     g 0 = b
     g z = if r == b - 1 then f (b + 1) n else g z'
           where (z', r) = divMod z b
-- Reinhard Zumkeller, Apr 12 2015

Crossrefs

Cf. A119353, A119354, A106370.

Sequence in context: A123699 A322808 A352899 * A205010 A204932 A079086

Adjacent sequences: A119349 A119350 A119351 * A119353 A119354 A119355

Keyword

base,nonn

Author

Franklin T. Adams-Watters, May 15 2006

Status

approved