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A005971
Partial sums of cubes of Lucas numbers.
(Formerly M5198)
1
1, 28, 92, 435, 1766, 7598, 31987, 135810, 574786, 2435653, 10316252, 43702500, 185123261, 784200368, 3321916912, 14071880655, 59609419066, 252509590018, 1069647725567, 4531100578950, 19194049901126, 81307300410353
OFFSET
1,2
REFERENCES
A. Brousseau, Fibonacci and Related Number Theoretic Tables. Fibonacci Association, San Jose, CA, 1972, p. 21.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
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.: (1+24*x-23*x^2-8*x^3)/((1-x)*(1+x-x^2)*(1-4*x-x^2)). - Ralf Stephan, Apr 23 2004
a(n) = A000032(3*n+2)/2+3*(-1)^n*A000032(n-1)+3/2. - Vaclav Kotesovec, Nov 19 2012
MAPLE
lucas := proc(n) option remember: if n=1 then RETURN(1) fi: if n=2 then RETURN(3) fi: lucas(n-1)+lucas(n-2) end: l[0] := 0: for i from 1 to 50 do l[i] := l[i-1]+lucas(i)^3; printf(`%d, `, l[i]) od: # James A. Sellers, May 29 2000
A005971:=(-1-24*z+23*z**2+8*z**3)/(z-1)/(z**2+4*z-1)/(z**2-z-1); # conjectured by Simon Plouffe in his 1992 dissertation
MATHEMATICA
Table[LucasL[3*n+2]/2+3*(-1)^n*LucasL[n-1]+3/2, {n, 1, 20}] (* Vaclav Kotesovec, Nov 19 2012 *)
CoefficientList[Series[(1 + 24 x - 23 x^2 - 8 x^3) / ((1-x) (1+x-x^2) (1-4*x-x^2)), {x, 0, 30}], x] (* Vincenzo Librandi, May 03 2013 *)
Accumulate[LucasL[Range[30]]^3] (* Harvey P. Dale, Oct 11 2021 *)
CROSSREFS
Sequence in context: A331765 A333280 A192256 * A189808 A130085 A211495
KEYWORD
nonn
EXTENSIONS
More terms from James A. Sellers, May 29 2000
Definition clarified by Harvey P. Dale, Oct 11 2021
STATUS
approved