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A030283
a(0) = 0; for n>0, a(n) is the smallest number greater than a(n-1) which does not use any digit used by a(n-1).
17
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 22, 30, 41, 50, 61, 70, 81, 90, 111, 200, 311, 400, 511, 600, 711, 800, 911, 2000, 3111, 4000, 5111, 6000, 7111, 8000, 9111, 20000, 31111, 40000, 51111, 60000, 71111, 80000, 91111, 200000, 311111, 400000, 511111, 600000
OFFSET
0,3
COMMENTS
The sequence is infinite.
LINKS
FORMULA
a(n) = a(n-2) + 10*a(n-8) - 10*a(n-10) for n > 29. - Nicolas Bělohoubek, Jul 01 2024
MATHEMATICA
a = {0}; For[n = 1, n < 1000000, n++, If[Length[Intersection[IntegerDigits[n], IntegerDigits[a[[ -1]]]]] == 0, AppendTo[a, n]]]; a (* Stefan Steinerberger, May 30 2007 *)
PROG
(Haskell)
a030283 n = a030283_list !! n
a030283_list = 0 : f 1 9 0 where
f u v w = w' : f u' v' w' where
w' = until (> w) ((+ v) . (* 10)) u
(u', v') = h u v
h 1 0 = (2, 2); h 9 0 = (1, 1); h 9 1 = (2, 0); h 9 9 = (1, 0)
h u 2 = (u+1, 0); h u v = (u+1, 1-v)
-- Reinhard Zumkeller, May 03 2012
CROSSREFS
KEYWORD
nonn,base,easy,nice
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of Rick L. Shepherd, Sep 27 2007
Definition clarified by Harvey P. Dale, Oct 19 2012
STATUS
approved