cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-12 of 12 results.

A282044 Reduced Kronecker coefficients for the case a=2, b=3, i=4.

Original entry on oeis.org

0, 0, 0, 0, 1, 2, 5, 9, 16, 24, 37, 51, 71, 93
Offset: 0

Views

Author

N. J. A. Sloane, Feb 21 2017

Keywords

Comments

Table 3 of Colmenarejo (2016) shows this sequence as the missing member of the family A266769, A000601, A006918, A014126, A282044, A175287.
It would be nice to have a g.f.

Crossrefs

Formula

Conjectured g.f.: x^4*(1+x^2)/(1-2*x+x^3+3*x^5-4*x^6). - Jean-François Alcover, Feb 18 2019.

A266771 Molien series for invariants of finite Coxeter group D_8 (bisected).

Original entry on oeis.org

1, 1, 2, 3, 6, 8, 13, 18, 27, 36, 51, 67, 92, 118, 156, 198, 256, 319, 404, 498, 620, 755, 926, 1116, 1353, 1615, 1935, 2291, 2720, 3194, 3759, 4384, 5120, 5932, 6879, 7923, 9131, 10458, 11981, 13654, 15561, 17648, 20014, 22600, 25514, 28692, 32255, 36134, 40464, 45167
Offset: 0

Views

Author

N. J. A. Sloane, Jan 10 2016

Keywords

Comments

The Molien series for the finite Coxeter group of type D_k (k >= 3) has G.f. = 1/Prod_i (1-x^(1+m_i)) where the m_i are [1,3,5,...,2k-3,k-1]. If k is even only even powers of x appear, and we bisect the sequence.

References

  • J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See Table 3.1, page 59.

Crossrefs

Molien series for finite Coxeter groups D_3 through D_12 are A266755, A266769, A266768, A003402, and A266770-A266775.

Programs

  • Mathematica
    Take[CoefficientList[Series[1/((1-x^8)Times@@(1-x^Range[2,14,2])),{x,0,100}],x],{1,-1,2}] (* Harvey P. Dale, Jan 02 2018 *)

Formula

G.f.: 1/((1-t^8)^2*(1-t^2)*(1-t^4)*(1-t^6)*(1-t^10)*(1-t^12)*(1-t^14)), bisected.
Previous Showing 11-12 of 12 results.