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 A090579 #9 Feb 09 2014 17:27:41
%S A090579 1,4,10,20,35,56,84,120,165,219,279,342,405,465,519,564,597,615,615,
%T A090579 597,564,519,465,405,342,279,219,165,120,84,56,35,20,10,4,1
%N A090579 Number of numbers with 4 decimal digits and sum of digits = n.
%C A090579 There are 9000 numbers with 4 decimal digits, the smallest being 1000 and the largest 9999.
%F A090579 G.f.: (x-x^10)/(1-x)*((1-x^10)/(1-x))^3. - _Geoffrey Critzer_, Feb 09 2014
%e A090579 a(2)=4: 1001, 1010, 1100, 2000.
%t A090579 nn=36;Drop[CoefficientList[Series[(x-x^10)/(1-x)(1-x^10)^3/(1-x)^3,{x,0,nn}],x],1] (* _Geoffrey Critzer_, Feb 09 2014 *)
%o A090579 (PARI) b=vector(36,i,0);for(n=1000,9999,a=eval(Vec(Str(n)));b[sum(j=1,4,a[j])]++);for(n=1,36,print1(b[n],",")) - Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 19 2006
%Y A090579 Cf. A071817 3-digit numbers, A090580 5-digit numbers, A090581 6-digit numbers.
%K A090579 base,fini,full,nonn
%O A090579 1,2
%A A090579 _Hugo Pfoertner_, Jan 12 2004