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 A099483 #9 May 23 2016 13:41:17
%S A099483 0,1,3,7,18,48,126,329,861,2255,5904,15456,40464,105937,277347,726103,
%T A099483 1900962,4976784,13029390,34111385,89304765,233802911,612103968,
%U A099483 1602508992,4195423008,10983760033,28755857091,75283811239,197095576626
%N A099483 A Fibonacci convolution.
%C A099483 A Chebyshev transform of the sequence 0,1,3,9,27 with g.f. x/(1-3x). The image of G(x) under the Chebyshev transform is (1/(1+x^2))G(x/(1+x^2)).
%H A099483 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2,3,-1).
%F A099483 G.f.: x/((1+x^2)(1-3x+x^2)); a(n)=3a(n-1)-2a(n-2)+3a(n-3); a(n)=sum{k=0..n, cos(pi*k/2)F(2(n-k))}. a(n)=sum{k=0..floor(n/2), binomial(n-k, k)(-1)^n*(3^(n-2k)-0^(n-2k))/3}.
%F A099483 (1/6) [2Fib(2n+2) - I^n - (-I)^n ]. - _Ralf Stephan_, Dec 04 2004
%t A099483 LinearRecurrence[{3,-2,3,-1},{0,1,3,7},30] (* _Harvey P. Dale_, May 23 2016 *)
%Y A099483 Cf. A000045, A099484, A099485.
%K A099483 easy,nonn
%O A099483 0,3
%A A099483 _Paul Barry_, Oct 18 2004