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A198486 Numbers with the property that all pairs of consecutive digits differ by 9.

%I A198486 #41 May 21 2021 04:13:44
%S A198486 1,2,3,4,5,6,7,8,9,90,909,9090,90909,909090,9090909,90909090,
%T A198486 909090909,9090909090,90909090909,909090909090,9090909090909,
%U A198486 90909090909090,909090909090909,9090909090909090,90909090909090909,909090909090909090,9090909090909090909
%N A198486 Numbers with the property that all pairs of consecutive digits differ by 9.
%H A198486 <a href="/A198486/b198486.txt">Table of n, a(n) for n = 1..27</a>
%t A198486 t = {1, 2, 3, 4, 5, 6, 7, 8, 9}; Do[AppendTo[t, 10*t[[-1]]]; AppendTo[t, 10*t[[-1]] + 9], {9}]; t (* _T. D. Noe_, Oct 22 2013 *)
%o A198486 (Python)
%o A198486 def A198486():
%o A198486     print('Numbers whose consecutive digits differ by 9')
%o A198486     for i in range(1, 100001):
%o A198486         b, n = True, i
%o A198486         if n > 9:
%o A198486             while n > 9:
%o A198486                 a = abs((n // 10) % 10 - n % 10)
%o A198486                 if a != 9: b = False
%o A198486                 n = n // 10
%o A198486         if b: print(i, end=', ')
%o A198486     return
%Y A198486 Cf. A033075, A033088, A033081, A048406-A048410.
%K A198486 nonn,base
%O A198486 1,2
%A A198486 _Pieter Stadhouders_, Oct 20 2013
%E A198486 More terms from _T. D. Noe_, Oct 22 2013