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A065563
Product of three consecutive Fibonacci numbers.
14
2, 6, 30, 120, 520, 2184, 9282, 39270, 166430, 704880, 2986128, 12649104, 53583010, 226980390, 961505790, 4073001576, 17253515288, 73087057560, 309601753890, 1311494059590, 5555578014142, 23533806080736, 99690802394400, 422297015565600, 1788878864806850, 7577812474550214
OFFSET
1,1
REFERENCES
Mohammad K. Azarian, Fibonacci Identities as Binomial Sums II, International Journal of Contemporary Mathematical Sciences, Vol. 7, No. 42, 2012, pp. 2053-2059.
Mohammad K. Azarian, Fibonacci Identities as Binomial Sums, International Journal of Contemporary Mathematical Sciences, Vol. 7, No. 38, 2012, pp. 1871-1876.
T. Koshy, Fibonacci and Lucas numbers with applications, Wiley, 2001, p. 89, No. 32, with a minus sign.
LINKS
V. E. Hoggatt and D. A. Lind, The Heights of Fibonacci Polynomials and an Associated Function, Fibonacci Quarterly, Vol. 5, No. 2 (April, 1967), pp. 141-152.
Joseph S. Ozbolt, A New Sequence Derived From a Combination of Cubes with Volume Fn^3, Fibonacci Quarterly, Vol. 50, No. 1 (2012), pp. 19-26.
FORMULA
a(n) = A000045(n)*A000045(n+1)*A000045(n+2).
G.f.: 2/(1 - 3*x - 6*x^2 + 3*x^3 + x^4).
a(n) = 2*A001655(n).
a(n) = Fibonacci(n+1)^3-(-1)^n*Fibonacci(n+1). - Gary Detlefs, Feb 02 2011
This corrects a sign mistake in the Koshy reference. - Wolfdieter Lang, Aug 07 2012
a(n) = 3*a(n-1) + 6*a(n-2) - 3*a(n-3) - a(n-4).
O.g.f.: 2*x/((1 + x - x^2)*(1 - 4*x - x^2)) (compare with A001655). - Wolfdieter Lang, Aug 06 2012
Sum_{n>=1} (-1)^(n+1)/a(n) = A079586 - 3. - Amiram Eldar, Oct 04 2020
Sum_{n>=1} 1/a(n) = A324007. - Amiram Eldar, Feb 09 2023
MAPLE
with (combinat):a:=n->fibonacci(n)*fibonacci(n+1)*fibonacci(n+2): seq(a(n), n=1..22); # Zerinvary Lajos, Oct 07 2007
MATHEMATICA
Times@@@Partition[Fibonacci[Range[30]], 3, 1] (* Harvey P. Dale, Aug 18 2011 *)
PROG
(PARI) a(n) = { fibonacci(n)*fibonacci(n + 1)*fibonacci(n + 2) } \\ Harry J. Smith, Oct 22 2009
(Magma) [&*[Fibonacci(n+k): k in [0..2] ]: n in [1..30]]; // Vincenzo Librandi, Apr 09 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Len Smiley, Nov 30 2001
EXTENSIONS
Offset changed from 0 to 1 by Harry J. Smith, Oct 22 2009
STATUS
approved