login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A133238 Dimensions of certain Lie algebra (see reference for precise definition). 2
1, 52, 1053, 12376, 100776, 627912, 3187041, 13748020, 51949755, 175847880, 542393670, 1544927904, 4107092288, 10278624864, 24388573014, 55188666312, 119696471453, 249869263644, 503865726155, 984563860280, 1869304764600, 3456658569000, 6238533257775 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

J. M. Landsberg and L. Manivel, The sextonions and E7 1/2, Adv. Math. 201 (2006), 143-179. [Th. 7.1, case a=1]

LINKS

Table of n, a(n) for n=0..22.

FORMULA

Empirical g.f.: (x^8+36*x^7+341*x^6+1208*x^5+1820*x^4+1208*x^3+341*x^2+36*x+1) / (x-1)^16. - Colin Barker, Jul 27 2013

MAPLE

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(1, k), k=0..30)];

CROSSREFS

The cases a = -4/3, -1, -2/3, 0, 1, 2, 4, 6, 8 of Th. 7.1 of Landsberg and Manivel give sequences A005408, A000578, A085462, A107942, A133238 (this entry), A133239, A133240, A133241 and A030650 respectively. See also triangle in A128894.

Sequence in context: A083936 A273655 A160288 * A331127 A216939 A130000

Adjacent sequences:  A133235 A133236 A133237 * A133239 A133240 A133241

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Oct 15 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 3 08:22 EDT 2022. Contains 357231 sequences. (Running on oeis4.)