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 A178914 #10 Sep 18 2024 08:33:48
%S A178914 10,9,8,7,6,5,4,3,2,1,90,89,88,87,86,85,84,83,82,81,80,79,78,77,76,75,
%T A178914 74,73,72,71,70,69,68,67,66,65,64,63,62,61,60,59,58,57,56,55,54,53,52,
%U A178914 51,50,49,48,47,46,45,44,43,42,41,40,39,38,37,36,35,34,33,32,31,30,29,28
%N A178914 10's complement of nonnegative numbers.
%C A178914 Apart from the initial a(0) a duplicate of A089186. - _R. J. Mathar_, Jun 25 2010
%F A178914 a(n) = 10^k - n where k is the number of digits in n.
%e A178914 a(11) = 10's complement of 11 = 89
%t A178914 Join[{10},Table[10^IntegerLength[n]-n,{n,80}]] (* _Harvey P. Dale_, Feb 06 2015 *)
%Y A178914 Cf. A089186.
%K A178914 base,easy,nonn
%O A178914 0,1
%A A178914 _Amarnath Murthy_, Jun 23 2010