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