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 A100814 #9 Jan 17 2017 09:05:14
%S A100814 9,87,654,3210,98765,432109,8765432,10987654,321098765,4321098765,
%T A100814 43210987654,321098765432,1098765432109,87654321098765,
%U A100814 432109876543210,9876543210987654,32109876543210987,654321098765432109
%N A100814 Digits 9 to 0 are written in order with increasing number of digits for each member of the sequence. Leading zeros are counted, but are not written down.
%C A100814 This is similar to A062273 and A007923
%D A100814 C. Ashbacher, "Some problems concerning the Smarandache deconstructive sequence", Journal of Recreational Mathematics, vol. 29(2), 82-84 (1998)
%D A100814 Russell Euler and Jawad Sadek, "Some divisibility patterns in the Smarandache deconstructive sequence", Journal of Recreational Mathematics, vol. 31(1), 12-14 (2002-2003)
%e A100814 The first number in the sequence is 9.
%e A100814 The second number in the sequence is 87.
%e A100814 The third number in the sequence is 654.
%t A100814 With[{c=PadRight[{},250,Range[9,0,-1]]},Table[FromDigits[Take[c,{(n(n+1))/2+1,((n+1)(n+2))/2}]],{n,0,20}]] (* _Harvey P. Dale_, Jan 17 2017 *)
%Y A100814 Cf. A007923, A062273.
%K A100814 nonn,easy,base
%O A100814 1,1
%A A100814 _Parthasarathy Nambi_, Jan 05 2005
%E A100814 More terms from _Robert G. Wilson v_ and _Lior Manor_, Jan 14 2005