%I #4 Sep 03 2022 21:32:01
%S 0,1,1,0,2,0,3,3,0,5,5,0,8,0,11,11,0,16,0,21,21,0,29,29,0,40,0,51,51,
%T 0,67,67,0,88,0,109,109,0,138,0,167,167,0,207,207,0,258,0,309,309,0,
%U 376,0,443,443,0,531,531,0,640,0,749,749,0,887,887,0,1054,0,1221,1221,0,1428
%N Second differences of A006336.
%C a(n) = A006336(n+2)-2*A006336(n+1)-A006336(n) = A134408(n+1)-A134408(n);
%C apart from 0 same range as A006336;
%C A001950(n) = Min(m: a(m) = A006336(n)).
%Y Cf. A001950, A006336, A134408.
%K nonn
%O 1,5
%A _Reinhard Zumkeller_, Oct 24 2007