%I #6 Jan 27 2022 22:22:30
%S 2,6,14,23,42,69,126,207,302,437,621,906,1275,1503,1863,2718,3825,
%T 4509,5589,6710,8303,10298,12026,13527,16767,20130,24225,28557,30894,
%U 35970,39501,40581,50301
%N (s(n)+s(n+1))/18, where s()=A006521.
%Y Cf. A006521.
%K nonn
%O 3,1
%A _Robert G. Wilson v_