|
|
A080041
|
|
a(n) = floor((1+sqrt(3))^n).
|
|
1
|
|
|
1, 2, 7, 20, 55, 152, 415, 1136, 3103, 8480, 23167, 63296, 172927, 472448, 1290751, 3526400, 9634303, 26321408, 71911423, 196465664, 536754175, 1466439680, 4006387711, 10945654784, 29904084991, 81699479552, 223207129087
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (1+2t^3)/( (t-1)*(1+t)*(2*t^2+2*t-1)).
|
|
MATHEMATICA
|
CoefficientList[Series[(1+2t^3)/(1-2t-3t^2+2t^3+2t^4), {t, 0, 30}], t]
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Mario Catalani (mario.catalani(AT)unito.it), Jan 21 2003
|
|
STATUS
|
approved
|
|
|
|