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A133350
Dimensions of certain Lie algebra (see reference for precise definition).
1
1, 90, 1274, 8568, 38115, 130130, 369460, 915552, 2043621, 4198810, 8065134, 14651000, 25393095, 42280434, 68000360, 106108288, 161222985, 239249178, 347629282, 495626040, 694637867, 958548690, 1304114076, 1751385440, 2324174125, 3050557146, 3963426390
OFFSET
0,2
LINKS
J. M. Landsberg and L. Manivel, The sextonions and E7 1/2, Adv. Math. 201 (2006), pp. 143-179. [Th. 7.2(iii), case a = 1]
FORMULA
Empirical g.f.: (14*x^5+273*x^4+840*x^3+582*x^2+82*x+1) / (x-1)^8. - Colin Barker, Jul 27 2013
MAPLE
b:=binomial; t72c:= proc(a, k) ((4*k+3*a+2)/((3*a+2)*(k+1))) * b(k+a, k)*b(k+a+1, k)*b(k+3*a/2-1, k)*b(k+3*a/2, k)*b(2*k+2*a+1, 2*k)/ (b(k+a/2-1, k)*b(k+a/2, k)*b(2*k+a, 2*k)); end; [seq(t72c(1, k), k=0..40)];
MATHEMATICA
t72c[a_, k_] := (4k+3a+2) / ((k+1)(3a+2)) Binomial[k+a, k] Binomial[k+a+1, k] Binomial[k+3/2a-1, k] Binomial[k+3/2a, k] Binomial[2k+2a+1, 2k] / (Binomial[k+a/2-1, k] Binomial[k+a/2, k] Binomial[2k+a, 2k]);
Array[t72c[1, #]&, 30, 0] (* Paolo Xausa, Jan 09 2024 *)
CROSSREFS
Sequence in context: A213455 A155016 A179800 * A279438 A250869 A234983
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 20 2007
STATUS
approved