Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #13 Jan 11 2024 11:10:03
%S 1,190,15504,749360,24732110,605537790,11619550320,181746027600,
%T 2386644625950,26923893369075,265762390788000,2330056309932000,
%U 18372187417457250,131651129456894250,865026329992488000,5251754282090616000,29657709797595709500,156694210053607278000
%N Dimensions of certain Lie algebra (see reference for precise definition).
%H Paolo Xausa, <a href="/A133241/b133241.txt">Table of n, a(n) for n = 0..10000</a>
%H J. M. Landsberg and L. Manivel, <a href="https://doi.org/10.1016/j.aim.2005.02.001">The sextonions and E7 1/2</a>, Adv. Math. 201 (2006), 143-179. [Th. 7.1, case a=6]
%p b:=binomial; t71:= proc(a,k) ((3*a+2*k+5)/(3*a+5)) * b(k+2*a+3,k)*b(k+5*a/2+3,k)*b(k+3*a+4,k)/(b(k+a/2+1,k)*b(k+a+1,k)); end; [seq(t71(6,k),k=0..30)];
%t t71[a_, k_] := (3a+2k+5) / (3a+5) Binomial[k+2a+3, k] Binomial[k+5/2a+3, k] Binomial[k+3a+4, k] / (Binomial[k+a/2+1, k] Binomial[k+a+1, k]);
%t Array[t71[6, #]&, 30, 0] (* _Paolo Xausa_, Jan 11 2024 *)
%K nonn
%O 0,2
%A _N. J. A. Sloane_, Oct 15 2007