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%I #6 Jan 30 2020 22:03:20
%S 1,1,4,20,117,770,5581,44023,375118,3434312,33632306,350894959,
%T 3885892547,45520247052,562266198499,7301972285296,99436168734138,
%U 1416444089850373,21059162813775906,326127491494213657
%N Convolution cube-root of column 2 (A127085) of triangle A127082.
%H G. C. Greubel, <a href="/A127088/b127088.txt">Table of n, a(n) for n = 0..80</a>
%t T[n_, k_]:= T[n, k]= If[k==n, 1, Coefficient[(1 + x*Sum[x^(r-k)*Sum[T[r, c], {c, k, r}], {r, k, n-1}] + x^(n+1))^(k+1), x, n-k]]; CoefficientList[Series[ (Sum[T[n, 2]*x^n, {n,0,25}]/x^2)^(1/3), {x,0,20}], x] (* _G. C. Greubel_, Jan 30 2020 *)
%Y Cf. A127082, A127083, A127084, A127085, A127086, A127087, A127089, A127090, A127091.
%K nonn
%O 0,3
%A _Paul D. Hanna_, Jan 04 2007