%I #8 Aug 01 2023 07:57:51
%S 0,0,2,1,2,0,2,2,2,2,4,1,2,1,3,3,2,2,4,3,4,0,2,2,2,2,4,2,3,2,4,4,2,2,
%T 4,3,4,2,4,4,4,4,6,1,2,1,3,3,2,2,4,3,4,1,3,3,3,3,5,3,4,3,5,5,2,2,4,3,
%U 4,2,4,4,4,4,6,3,4,3,5,5,4,4,6,5,6,0
%N Central terms of the triangle in A240857.
%H Reinhard Zumkeller, <a href="/A240883/b240883.txt">Table of n, a(n) for n = 0..10000</a>
%F a(n) = A240857(2*n,n) = A046818(n) - 1.
%t a[n_] := DigitCount[3*n + 1, 2, 1] - 1; Array[a, 100, 0] (* _Amiram Eldar_, Aug 01 2023 *)
%o (Haskell)
%o a240883 n = a240857 (2 * n) n
%Y Cf. A046818, A240857.
%K nonn
%O 0,3
%A _Reinhard Zumkeller_, Apr 14 2014