|
| |
|
|
A092236
|
|
(3^n + 2*3^(n/2)*cos(n*Pi/6))/3.
|
|
0
| |
|
|
1, 2, 4, 9, 24, 72, 225, 702, 2160, 6561, 19764, 59292, 177633, 532170, 1595052, 4782969, 14346720, 43040160, 129127041, 387400806, 1162241784, 3486784401, 10460412252, 31381236756, 94143533121, 282430067922, 847289140884, 2541865828329, 7625595890664
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| From an Internat. Math. Olympiad problem.
|
|
|
REFERENCES
| E. Lozansky and C. Rousseau, Winning Solutions, Springer, 1996; see p. 154.
|
|
|
FORMULA
| G.f.: (1-4x+4x^2) / [(1-3x)(1-3x+3x^2)].
|
|
|
CROSSREFS
| Sequence in context: A148084 A156804 A081913 * A009283 A125654 A141824
Adjacent sequences: A092233 A092234 A092235 * A092237 A092238 A092239
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Feb 18 2004
|
| |
|
|
