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A092203 Molien series for 16-dimensional group of structure 2^4.O_{4}^{+}(F_2) = 2^4.(S_3 X S_3).2 and order 1152, corresponding to genus 2 complete weight enumerators of Hermitian self-dual GF(2)-linear codes over GF(4) containing the all-ones vector. 1
1, 1, 3, 7, 21, 47, 128, 303, 754, 1735, 3989, 8712, 18687, 38482, 77421, 150813, 286925, 531306, 962637, 1704506, 2959412, 5037606, 8426351, 13854300, 22426944, 35759968, 56234440, 87258555, 133730542, 202529129, 303328391, 449478982, 659401717, 958118335, 1379571974, 1969206260 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
G. Nebe, E. M. Rains and N. J. A. Sloane, Self-Dual Codes and Invariant Theory, Springer, Berlin, 2006. See Section (7.6.1), and especially Eq. (7.6.14) on page 219.
FORMULA
For the Molien series see the Maple code.
MAPLE
f1:= 1 + t^3 + 5*t^4 + 18*t^5 + 45*t^6 + 88*t^7 + 196*t^8 + 394*t^9 + 804*t^10 + 1512*t^11 + 2702*t^12 + 4529*t^13 + 7218*t^14 + 11019*t^15 + 16064*t^16 + 22609*t ^17 + 30555*t^18 + 39889*t^19 + 50303*t^20 + 61476*t^21 + 72888*t^22 + 84047*t^23 + 94299*t^24 + 102995*t^25 + 109674*t^26 + 113791*t^27 + 57614*t^28;
f:= f1+expand(t^56*subs(t=1/t, f1));
g:= (1-t)*(1-t^2)^2*(1-t^3)^3*(1-t^4)^6*(1-t^6)*(1-t^8)^2*(1-t^12);
h:=f/g; # This is the Molien series
series(h, t, 48);
CROSSREFS
Sequence in context: A183936 A027151 A219589 * A018760 A050614 A181393
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 02 2004
EXTENSIONS
There were errors in the definition (in the order and structure of the group). The rational form of the Molien series was correct, but the DATA section - the coefficients in the expansion of the Molien series - was wrong from the 28th term onwards. To make it easier to check I have replaced the formulas with Maple code based on the Latex source code for the book. Thanks to Georg Fischer and Andrey Zabolotskiy for noticing that something was wrong and proposing corrections. - N. J. A. Sloane, Jan 29 2021
STATUS
approved

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Last modified April 24 15:42 EDT 2024. Contains 371960 sequences. (Running on oeis4.)