This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A043537 #37 Dec 02 2021 02:12:50 %S A043537 1,1,1,1,1,1,1,1,1,2,1,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,1,2, %T A043537 2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,1,2,2, %U A043537 2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,1,2,2 %N A043537 Number of distinct base-10 digits of n. %C A043537 a(A000079(A130694(n))) = 10. - _Reinhard Zumkeller_, Jul 29 2007 %C A043537 a(A000290(A016070(n))) = 2. - _Reinhard Zumkeller_, Aug 05 2010 %C A043537 a(n) = 10 for almost all n. - _Charles R Greathouse IV_, Oct 02 2013 %H A043537 R. Zumkeller, <a href="/A043537/b043537.txt">Table of n, a(n) for n = 1..10000</a> %p A043537 A043537 := proc(n) %p A043537 convert(convert(n,base,10),set) ; %p A043537 nops(%) ; %p A043537 end proc: # _R. J. Mathar_, Dec 22 2012 %t A043537 Count[DigitCount@ #, n_ /; n > 0] & /@ Range@ 120 (* _Michael De Vlieger_, Aug 29 2015 *) %o A043537 (Haskell) %o A043537 import Data.List (nub) %o A043537 a043537 = length . nub . show -- _Reinhard Zumkeller_, Apr 16 2011 %o A043537 (PARI) a(n)=#vecsort(digits(n),,8) \\ _Charles R Greathouse IV_, Oct 02 2013 %o A043537 (Python) %o A043537 def A043537(n): return len(set(str(n))) # _Dimiter Skordev_, Oct 02 2021 %Y A043537 Cf. A047726, A118668, A119797, A119798, A119799, A119823, A038378, A076493, A055642, A178788. %K A043537 nonn,base,easy %O A043537 1,10 %A A043537 _Clark Kimberling_