%I #8 Jul 21 2019 19:12:31
%S 1,2,4,11,28,68,169,470,1276,3395,9016,25736,71785,197084,543136,
%T 1562987,4441888,12490268,35118241,102094436,293497252,836212259,
%U 2384733976,6972232316,20220310225,58240787582,167689305760,493029967907,1438787149228
%N a(n) = A024741(n+3)/6.
%Y Cf. A024741.
%K nonn
%O 1,2
%A _Clark Kimberling_
%E a(28) corrected by _Sean A. Irvine_, Jul 21 2019