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 A208976 #14 Feb 03 2018 09:55:51
%S A208976 1,2,4,8,15,29,54,104,195,377,713,1385,2639,5147,9866,19304,37179,
%T A208976 72929,140997,277133,537471,1058147,2057509,4056233,7904455,15600899,
%U A208976 30458899,60174899,117675359,232676279,455657714,901620584,1767883499,3500409329,6871173869
%N A208976 Row sums of the triangle in A208101.
%C A208976 a(n) = A050168(n+1) - 1.
%C A208976 Number of Dyck (n+1)-paths that are symmetric after deleting all leading hills. - _David Scambler_, Aug 23 2012
%H A208976 Reinhard Zumkeller, <a href="/A208976/b208976.txt">Table of n, a(n) for n = 0..1000</a>
%F A208976 a(n) = A001405(n) + A001405(n+1) - 1.
%t A208976 T[_, 0] = 1; T[n_, 1] := n; T[n_, n_] := T[n - 1, n - 2]; T[n_, k_] /; 1 < k < n := T[n, k] = T[n - 1, k] + T[n - 1, k - 2];
%t A208976 a[n_] := Sum[T[n, k], {k, 0, n}];
%t A208976 Table[a[n], {n, 0, 40}] (* _Jean-François Alcover_, Feb 03 2018, from A208101 *)
%o A208976 (Haskell)
%o A208976 a208976 n = a208976_list !! n
%o A208976 a208976_list = map (subtract 1) $ tail a050168_list
%K A208976 nonn
%O A208976 0,2
%A A208976 _Reinhard Zumkeller_, Mar 04 2012