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 A127323 #5 Jul 11 2015 16:56:06
%S A127323 0,0,0,1,1,0,0,1,1,0,1,1,2,2,2,0,0,1,1,0,1,1,2,2,2,0,1,1,2,2,2,3,3,3,
%T A127323 3,0,0,1,1,0,1,1,2,2,2,0,1,1,2,2,2,3,3,3,3,0,1,1,2,2,2,3,3,3,3,4,4,4,
%U A127323 4,4,0,0,1,1,0,1,1,2,2,2,0,1,1,2,2,2,3,3,3,3,0,1,1,2,2,2,3,3,3,3,4,4,4,4,4
%N A127323 Third 4-dimensional hyper-tetrahedral coordinate; 4-D analog of A056557.
%C A127323 If {(W,X,Y,Z)} are 4-tuples of nonnegative integers with W>=X>=Y>=Z ordered by W, X, Y and Z, then W=A127321(n), X=A127322(n), Y=A127323(n) and Z=A127324(n). These sequences are the four-dimensional analogs of the three-dimensional A056556, A056557 and A056558.
%F A127323 For W>=X>=0, a(A000332(W+3)+A000292(X)+A000217(Y)) = a(A000332(W+3)+A000292(X)+A000217(Y+1)-1) = Y A127322(n+1) = A127321(n)==A127324(n) ? 0 : A127322(n)==A127324(n) ? 0 : A127323(n)==A127324(n) ? A127323(n)+1 : A127323(n)
%e A127323 a(23)=2 because a(A000332(2+3)+A000292(2)+A000217(2)) = a(A000332(2+3)+A000292(2)+A000217(2+1)-1) = 2, so a(22) = a(24) = 2.
%e A127323 See A127321 for a table of A127321, A127322, A127323, A127324.
%Y A127323 Cf. A127321, A127322, A127324, A056556, A056557, A056558, A000332, A000292, A000217.
%K A127323 nonn
%O A127323 0,13
%A A127323 _Graeme McRae_, Jan 10 2007