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 A102516 #8 Aug 06 2018 17:50:55
%S A102516 0,1,2,3,4,5,6,8,13,24,45,81,138,224,352,546,851,1348,2175,3556,5843,
%T A102516 9582,15624,25317,40836,65737,105863,170796,276160,447272,724968,
%U A102516 1174985,1903186,3080367,4982688,8057421,13029534,21074012,34094041
%N A102516 Sum C(n-3k,3k+1), k=0..floor(n/6).
%H A102516 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1,0,0,1).
%F A102516 G.f.: x(1-x)/((1-x)^3-x^6); a(n)=sum{k=0..floor(n/6), C(n-3k, 3k+1)}.
%t A102516 LinearRecurrence[{3,-3,1,0,0,1},{0,1,2,3,4,5},40] (* _Harvey P. Dale_, Aug 06 2018 *)
%Y A102516 Cf. A101551.
%K A102516 easy,nonn
%O A102516 0,3
%A A102516 _Paul Barry_, Jan 13 2005