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 A061474 #5 Jul 12 2015 18:17:18
%S A061474 5,50,61,72,83,94,104,115,126,137,148,159,203,214,225,236,247,258,269,
%T A061474 302,313,324,335,346,357,368,379,401,412,423,434,445,456,467,478,489,
%U A061474 500,511,522,533,544,555,566,577,588,599,610,621,632,643,654,665,676
%N A061474 First (leftmost) digit - second digit + third digit - fourth digit .... = 5.
%H A061474 Harvey P. Dale, <a href="/A061474/b061474.txt">Table of n, a(n) for n = 1..1000</a>
%t A061474 Select[Range[1000],Total[Times@@@Partition[Riffle[IntegerDigits[#],{1,-1},{2,-1,2}],2]]==5&] (* _Harvey P. Dale_, Jul 12 2015 *)
%Y A061474 Cf. A008593, A060978-A060980, A060982, A061470-A061479, A061870-A061882.
%K A061474 nonn,base,easy
%O A061474 1,1
%A A061474 _Amarnath Murthy_, May 05 2001
%E A061474 More terms from _Robert G. Wilson v_, May 10 2001 and from Larry Reeves (larryr(AT)acm.org), May 14 2001