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 A061473 #5 Jan 27 2014 11:44:49
%S A061473 4,40,51,62,73,84,95,103,114,125,136,147,158,169,202,213,224,235,246,
%T A061473 257,268,279,301,312,323,334,345,356,367,378,389,400,411,422,433,444,
%U A061473 455,466,477,488,499,510,521,532,543,554,565,576,587,598,620,631,642
%N A061473 First (leftmost) digit - second digit + third digit - fourth digit .... = 4.
%H A061473 Harvey P. Dale, <a href="/A061473/b061473.txt">Table of n, a(n) for n = 1..1000</a>
%t A061473 Select[Range[700],Total[Times@@@Partition[Riffle[IntegerDigits[#],{1,-1},{2,-1,2}],2]]==4&] (* _Harvey P. Dale_, Jan 27 2014 *)
%Y A061473 Cf. A008593, A060978-A060980, A060982, A061470-A061479, A061870-A061882.
%K A061473 nonn,base,easy
%O A061473 1,1
%A A061473 _Amarnath Murthy_, May 05 2001
%E A061473 More terms from _Robert G. Wilson v_, May 10 2001 and from Larry Reeves (larryr(AT)acm.org), May 14 2001