|
|
A039826
|
|
Largest coefficient in expansion of Product_{i=1..n} (1 + q^i + q^(2i)).
|
|
3
|
|
|
1, 2, 3, 7, 15, 36, 87, 217, 549, 1423, 3735, 9911, 26513, 71581, 194681, 532481, 1464029, 4045117, 11225159, 31268577, 87404465, 245101771, 689323849, 1943817227, 5494808425, 15568077235, 44200775239, 125739619467, 358347118257, 1022994133467, 2925044957099, 8376049588815, 24018964753341
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
nmax = 28; d = {1}; a1 = {};
Do[
n0s = Table[0, {n}];
d = Join[d, n0s, n0s] + Join[n0s, d, n0s] + Join[n0s, n0s, d];
AppendTo[a1, Last[Union[d]]];
, {n, nmax}];
|
|
PROG
|
(PARI) a(n)=vecmax(Vec(prod(k=1, n, 1+x^k+x^(2*k))));
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|