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 A061878 #7 Nov 21 2013 12:47:30
%S A061878 9,90,108,119,207,218,229,306,317,328,339,405,416,427,438,449,504,515,
%T A061878 526,537,548,559,603,614,625,636,647,658,669,702,713,724,735,746,757,
%U A061878 768,779,801,812,823,834,845,856,867,878,889,900,911,922,933,944,955
%N A061878 |First digit - second digit + third digit - fourth digit ...| = 9.
%C A061878 Differs from A061478 at the 59th term.
%t A061878 Do[ a = IntegerDigits[ n ]; l = Length[ a ]; e = o = {}; Do[ o = Append[ o, a[ [ 2k - 1 ] ]], {k, 1, l/2 + .5} ]; Do[ e = Append[ e, a[ [ 2k ] ] ], {k, 1, l/2} ]; If[ Abs[ Apply[ Plus, o ] - Apply[ Plus, e ] ] == 9, Print[ n ] ], {n, 1, 1500} ]
%t A061878 ds9Q[n_]:=Module[{idn=IntegerDigits[n],ker}, ker=Table[(-1)^i, {i,2,Length[idn]+1}]; First[ListCorrelate[ker,idn]]==9]; Select[Range[1000],ds9Q] (* _Harvey P. Dale_, Feb 14 2011 *)
%Y A061878 Cf. A008593, A060978-A060980, A060982, A061470-A061479, A061870-A061882.
%K A061878 nonn,base,easy
%O A061878 1,1
%A A061878 _Robert G. Wilson v_, May 10 2001
%E A061878 More terms from Larry Reeves (larryr(AT)acm.org), May 15 2001