|
Search: id:A006497
|
|
|
| A006497 |
|
a(n) = 3a(n-1) + a(n-2). (Formerly M0910)
|
|
+0 5
|
|
| 2, 3, 11, 36, 119, 393, 1298, 4287, 14159, 46764, 154451, 510117, 1684802, 5564523, 18378371, 60699636, 200477279, 662131473, 2186871698, 7222746567, 23855111399, 78788080764, 260219353691, 859446141837, 2838557779202
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
REFERENCES
|
S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures}, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
A. F. Horadam, Generating identities for generalized Fibonacci and Lucas triples, Fib. Quart., 15 (1977), 289-292.
|
|
LINKS
|
S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures}, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
Tanya Khovanova, Recursive Sequences
Index entries for recurrences a(n) = k*a(n - 1) +/- a(n - 2)
Index entries for sequences related to Chebyshev polynomials.
|
|
FORMULA
|
a(n) = [(3 + sqrt13)/2]^n + [(3 - sqrt13)/2]^n; A006190(n-2) + A006190(n) = a(n-1); [a(n)]^2 - 13[A006190(n)]^2 = 4(-1)^n. - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jun 15 2003
E.g.f. : 2exp(3x/2)cosh(sqrt(13)x/2); a(n)=2^(1-n)sum{k=0..floor(n/2), C(n, 2k)13^k3^(n-2k)}. a(n)=2T(n, 3i/2)(-i)^n with T(n, x) Chebyshev's polynomials of the first kind (see A053120) and i^2=-1. - Paul Barry (pbarry(AT)wit.ie), Nov 15 2003
|
|
MAPLE
|
A006497:=(-2+3*z)/(-1+3*z+z**2); [Conjectured by S. Plouffe in his 1992 dissertation.]
|
|
CROSSREFS
|
Cf. A006190.
Cf. A100230.
Sequence in context: A080155 A032357 A062630 this_sequence A038912 A019361 A093804
Adjacent sequences: A006494 A006495 A006496 this_sequence A006498 A006499 A006500
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
njas
|
|
EXTENSIONS
|
More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Feb 14 2004
|
|
|
Search completed in 0.002 seconds
|