cp's OEIS Frontend

A357118 Numbers such that the first digit is the number of digits and the second digit is the number of distinct digits.

%I A357118 #42 Nov 12 2022 01:36:44
%S A357118 322,323,4222,4224,4242,4244,4300,4303,4304,4311,4313,4314,4322,4323,
%T A357118 4324,4330,4331,4332,4335,4336,4337,4338,4339,4340,4341,4342,4345,
%U A357118 4346,4347,4348,4349,4353,4354,4355,4363,4364,4366,4373,4374,4377,4383,4384,4388,4393,4394,4399
%N A357118 Numbers such that the first digit is the number of digits and the second digit is the number of distinct digits.
%C A357118 By definition, each term must be at least a two-digit number.
%C A357118 The sequence is finite. The last term is 989765432.
%C A357118 There are 11041830 terms. - _Michael S. Branicky_, Oct 20 2022
%H A357118 Michael S. Branicky, <a href="/A357118/b357118.txt">Table of n, a(n) for n = 1..10000</a>
%e A357118 322 is a term because the first digit is the number of digits = 3, and the second digit counts the different digits {2,3} = 2.
%o A357118 (Python)
%o A357118 def ok(n):
%o A357118     s = str(n)
%o A357118     if len(s) < 2 or len(s) > 9: return False
%o A357118     return len(s) == int(s[0]) and len(set(s)) == int(s[1])
%o A357118 print([k for k in range(4394) if ok(k)]) # _Michael S. Branicky_, Oct 17 2022
%Y A357118 Cf. A319678.
%K A357118 nonn,base,fini
%O A357118 1,1
%A A357118 _Marc Morgenegg_, Oct 17 2022