|
Search: id:A101399
|
|
|
| A101399 |
|
a(0) = 1, a(1) = 2, a(2) = 5; for n >= 3, a(n) = a(n - 1) + 2*a(n - 2) + a(n - 3) |
|
+0
6
|
|
| 1, 2, 5, 10, 22, 47, 101, 217, 466, 1001, 2150, 4618, 9919, 21305, 45761, 98290, 211117, 453458, 973982, 2092015, 4493437, 9651449, 20730338, 44526673, 95638798, 205422482, 441226751, 947710513, 2035586497, 4372234274
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Lengths of successive words (starting with a) under the substitution: {a -> ab, b -> aac, c -> a}.
|
|
MATHEMATICA
|
a[0] = 1; a[1] = 2; a[2] = 5; a[n_] := a[n] = a[n - 1] + 2a[n - 2] + a[n - 3]; Table[ a[n], {n, 0, 30}] (from Robert G. Wilson v Jan 15 2005)
|
|
CROSSREFS
|
Pairwise sums of A078007. Bisection of A003410 and A058278.
Adjacent sequences: A101396 A101397 A101398 this_sequence A101400 A101401 A101402
Sequence in context: A100938 A018004 A124329 this_sequence A018109 A123491 A038149
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
J. F. J. Laros (jlaros(AT)liacs.nl), Jan 15 2005
|
|
EXTENSIONS
|
More terms from Robert G. Wilson v (rgwv(AT)rgwv.com) and Lior Manor (lior.manor(AT)gmail.com) Jan 15 2005
|
|
|
Search completed in 0.002 seconds
|
