A292752 Dimensions of centralizer algebras of groups associated with Z_4-codes.

1, 1, 3, 16, 108, 811, 6513, 54706, 472818, 4157701, 36931023, 329937796, 2957233128, 26554062991, 238681391133, 2146606641286, 19311830377038, 173768326420681, 1563724202922843, 14072564151989176, 126648308996320548, 1139810939108974771, 10258179242691222153, 92323017137773245466

Offset

0,3

References

M. Kosuda and M. Oura, Centralizer algebras of the group associated to Z_4-codes, Discrete Math., 340 (2017), 2437-2446.

Links

Colin Barker, Table of n, a(n) for n = 0..1000

M. Kosuda and M. Oura, Centralizer algebras of the group associated to Z_4-codes, arXiv:1608.08731 [math.RT], 2016-2017.

Index entries for linear recurrences with constant coefficients, signature (15,-59,45).

Formula

For n>0, a(n) = (57+6*5^n+9^n)/96.

From Colin Barker, Sep 25 2017: (Start)

G.f.: (1 - 14*x + 47*x^2 - 15*x^3) / ((1 - x)*(1 - 5*x)*(1 - 9*x)).

a(n) = 15*a(n-1) - 59*a(n-2) + 45*a(n-3) for n>3.

(End)

Prog

(PARI) a(n) = if (n==0, 1, (57+6*5^n+9^n)/96); \\ Michel Marcus, Sep 25 2017
(PARI) Vec((1 - 14*x + 47*x^2 - 15*x^3) / ((1 - x)*(1 - 5*x)*(1 - 9*x)) + O(x^30)) \\ Colin Barker, Sep 25 2017

Crossrefs

Sequence in context: A369694 A074551 A135074 * A220379 A191800 A286764

Adjacent sequences: A292749 A292750 A292751 * A292753 A292754 A292755

Keyword

nonn,easy

Author

N. J. A. Sloane, Sep 24 2017

Extensions

More terms from Michel Marcus, Sep 25 2017

Status

approved