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A127128 Column 1 of triangle A127126. 11

%I #9 Jan 28 2020 12:08:30

%S 1,2,9,54,412,3834,42131,533558,7645065,122177706,2153221318,

%T 41464853266,865908079369,19484990264956,469910189792853,

%U 12089047867952058,330423404118495975,9561012695542004496

%N Column 1 of triangle A127126.

%C Convolution square of A127131.

%H G. C. Greubel, <a href="/A127128/b127128.txt">Table of n, a(n) for n = 1..80</a>

%t T[n_, k_]:= T[n, k]= If[k==n, 1, Coefficient[(1 +x*Sum[x^(r-k-1)*Sum[T[r, c], {c,k+1,r}], {r,k+1,n}] + x^(n+1))^(k+1), x, n-k]]; Table[T[n, 1], {n, 1, 20}] (* _G. C. Greubel_, Jan 28 2020 *)

%Y Cf. A127126; A127131; other columns: A127127, A127129, A127130.

%K nonn

%O 1,2

%A _Paul D. Hanna_, Jan 05 2007

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Last modified March 28 04:05 EDT 2024. Contains 371235 sequences. (Running on oeis4.)