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A001947
a(n) = Lucas(5*n+2).
(Formerly M3120 N1265)
1
3, 29, 322, 3571, 39603, 439204, 4870847, 54018521, 599074578, 6643838879, 73681302247, 817138163596, 9062201101803, 100501350283429, 1114577054219522, 12360848946698171, 137083915467899403, 1520283919093591604, 16860207025497407047, 186982561199565069121
OFFSET
0,1
COMMENTS
Related to Bernoulli numbers.
REFERENCES
J. Riordan, Combinatorial Identities, Wiley, 1968, p. 141.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Tanya Khovanova, Recursive Sequences
Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992; arXiv:0911.4975 [math.NT], 2009.
Simon Plouffe, 1031 Generating Functions, Appendix to Thesis, Montreal, 1992
FORMULA
G.f.: (3 - 4*x) / (1 - 11*x - x^2). - Corrected by Colin Barker, Apr 22 2017
a(n) = Lucas(5*n+2). - Thomas Baruchel, Nov 26 2003
From Colin Barker, Apr 22 2017: (Start)
a(n) = (((11-5*sqrt(5))/2)^n*(-5+3*sqrt(5)) + (5+3*sqrt(5))*((11+5*sqrt(5))/2)^n) / (2*sqrt(5)).
a(n) = 11*a(n-1) + a(n-2) for n>1.
(End)
MAPLE
A001947:=(-3+4*z)/(-1+11*z+z**2); # Conjectured by Simon Plouffe in his 1992 dissertation.
MATHEMATICA
LucasL[5*Range[0, 20]+2] (* Harvey P. Dale, Jan 18 2012 *)
PROG
(Magma) [ Lucas(5*n +2): n in [0..120]]; // Vincenzo Librandi, Apr 16 2011
(PARI) Vec((3 - 4*x) / (1 - 11*x - x^2) + O(x^20)) \\ Colin Barker, Apr 22 2017
CROSSREFS
Sequence in context: A155651 A268020 A278934 * A323569 A049038 A091646
KEYWORD
nonn,easy
STATUS
approved