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%I #16 Feb 19 2020 15:12:36
%S 0,1,0,0,2,1,1,0,0,0,3,2,2,1,1,1,0,0,0,0,4,3,3,2,2,2,1,1,1,1,0,0,0,0,
%T 0,5,4,4,3,3,3,2,2,2,2,1,1,1,1,1,0,0,0,0,0,0,6,5,5,4,4,4,3,3,3,3,2,2,
%U 2,2,2,1,1,1,1,1,1,0,0,0,0,0,0,0,7,6,6,5,5,5,4,4,4,4,3,3,3,3,3,2,2,2,2,2,2
%N Tetrahedron with T(t,n,k) = t - n; succession of growing finite triangles with declining values per row.
%H Peter Luschny, <a href="/A056559/b056559.txt">Table of n, a(n) for n = 0..10000</a> (first 105 terms by Henry Bottomley).
%F a(n) = A056556(n) - A056557(n).
%e First triangle: [0]; second triangle: [1; 0 0]; third triangle: [2; 1 1; 0 0 0]; ...
%o (Julia)
%o function a_list(N)
%o a = Int[]
%o for n in 1:N
%o for j in ((k:-1:1) for k in 1:n)
%o t = n - j[1]
%o for m in j
%o push!(a, t)
%o end end end; a end
%o A = a_list(10) # _Peter Luschny_, Feb 19 2020
%Y Together with A056558 and A056560 might enable reading "by antidiagonals" of cube arrays as 3-dimensional analog of A002262 and A025581 with square arrays.
%Y Bisection (y-coordinates) of A332662.
%K nonn,look
%O 0,5
%A _Henry Bottomley_, Jun 26 2000
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