|
|
A226264
|
|
Number of additive Z_2 Z_8 codes of a certain type (see Siap-Aydogdu for precise definition).
|
|
9
|
|
|
36, 84, 180, 372, 756, 1524, 3060, 6132, 12276, 24564, 49140, 98292, 196596, 393204, 786420, 1572852, 3145716, 6291444, 12582900, 25165812, 50331636, 100663284, 201326580, 402653172, 805306356, 1610612724, 3221225460, 6442450932, 12884901876, 25769803764
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
N2×8(r+1, 2; r, 1, 1, 0) r>=1. (Siap-Aydogdu Table 1)
|
|
LINKS
|
|
|
FORMULA
|
G.f.: 12*x*(3 - 2*x) / ((1 - x)*(1 - 2*x)).
a(n) = 12*(2^(1+n) - 1) for n>0.
a(n) = 3*a(n-1) - 2*a(n-2) for n>2.
(End)
|
|
MATHEMATICA
|
QP = QPochhammer;
a[n_] := 2(6(2^(n+3))^n QP[2^(-n-1), 2, n])/((2^(n+2))^n QP[2^-n, 2, n]);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|