cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A163198 Sum of the cubes of the first n even-indexed Fibonacci numbers.

Original entry on oeis.org

0, 1, 28, 540, 9801, 176176, 3162160, 56744793, 1018249596, 18271762300, 327873509425, 5883451505856, 105574253853888, 1894453118539345, 33994581881622076, 610008020755286076, 10946149791725643705, 196420688230338021808, 3524626238354441796016, 63246851602149831726825
Offset: 0

Views

Author

Stuart Clary, Jul 24 2009

Keywords

Comments

Natural bilateral extension (brackets mark index 0): ..., 9801, 540, 28, 1, 0, [0], 1, 28, 540, 9801, 176176, ... This is A163198-reversed followed by A163198. That is, A163198(-n) = A163198(n-1).

Crossrefs

Programs

  • Mathematica
    a[n_Integer] := If[ n >= 0, Sum[ Fibonacci[2k]^3, {k, 1, n} ], -Sum[ Fibonacci[-2k]^3, {k, 1, -n - 1} ] ]
    LinearRecurrence[{22, -77, 77, -22, 1}, {0, 1, 28, 540, 9801}, 50] (* G. C. Greubel, Dec 09 2016 *)
    Accumulate[Fibonacci[Range[0,40,2]]^3] (* Harvey P. Dale, Nov 15 2023 *)
  • PARI
    a(n) = sum(k=1, n, fibonacci(2*k)^3); \\ Michel Marcus, Feb 29 2016
    
  • PARI
    concat([0], Vec(x*(1 + 6*x + x^2)/((1 - x)*(1 - 3*x + x^2 )*(1 - 18*x + x^2)) + O(x^50))) \\ G. C. Greubel, Dec 09 2016

Formula

Let F(n) be the Fibonacci number A000045(n) and let L(n) be the Lucas number A000032(n).
a(n) = Sum_{k=1..n} F(2k)^3.
a(n) = A163199(n) + 1.
a(n) = (1/20)*(F(6n+3) - 12*F(2n+1) + 10).
a(n) = (1/4)*(F(2n+1)^3 - 3*F(2n+1) + 2). (K. Subba Rao)
a(n) = (1/4)*F(n)^2*L(n+1)^2*F(n-1)*L(n+2) = A163195(n) if n is even.
a(n) = (1/4)*L(n)^2*F(n+1)^2*L(n-1)*F(n+2) = A163197(n) if n is odd.
a(n) - 21 a(n-1) + 56 a(n-2) - 21 a(n-3) + a(n-4) = 8.
a(n) - 22 a(n-1) + 77 a(n-2) - 77 a(n-3) + 22 a(n-4) - a(n-5) = 0.
G.f.: (x + 6*x^2 + x^3)/(1 - 22*x + 77*x^2 - 77*x^3 + 22*x^4 - x^5) = x*(1 + 6*x + x^2)/((1 - x)*(1 - 3*x + x^2 )*(1 - 18*x + x^2)).
a(n) = (F(2*n+1)-1)^2*(F(2*n+1) + 2)/4, n>=0. See the Melham reference for a general conjecture. - Wolfdieter Lang, Aug 10 2012

Extensions

Melham and Ozeki references from Wolfdieter Lang, Aug 10 2012. Also Prodinger reference added, Oct 11 2012.

A163194 a(n) = F(n)^2 * L(n+1)^2 * F(n-1) * L(n+2), where F(n) and L(n) are the Fibonacci and Lucas numbers, respectively.

Original entry on oeis.org

0, 0, 112, 2156, 39204, 704700, 12648640, 226979168, 4072998384, 73087049196, 1311494037700, 23533806023420, 422297015415552, 7577812474157376, 135978327526488304, 2440032083021144300, 43784599166902574820, 785682752921352087228, 14098504953417767184064, 252987406408599326907296
Offset: 0

Views

Author

Stuart Clary, Jul 24 2009

Keywords

Comments

Natural bilateral extension (brackets mark index 0): ..., 39200, 2160, 108, 4, -4, [0], 0, 112, 2156, 39204, 704700, ... This is A163196-reversed followed by A163194. That is, A163194(-n) = A163196(n-1).

Examples

			G.f. = 112*x^2 + 2156*x^3 + 39204*x^4 + 704700*x^5 + 12648640*x^6 + ...
		

References

  • Stuart Clary and Paul D. Hemenway, On sums of cubes of Fibonacci numbers, Applications of Fibonacci Numbers, Vol. 5 (St. Andrews, 1992), 123-136, Kluwer Acad. Publ., 1993. See equation (3).

Crossrefs

Programs

  • Magma
    [(Fibonacci(n)*Lucas(n+1))^2*(Fibonacci(n-1)*Lucas(n+2)): n in [0..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    a[n_Integer] := Fibonacci[n]^2 LucasL[n+1]^2 Fibonacci[n-1] LucasL[n+2]
    LinearRecurrence[{20, -35, -35, 20, -1}, {0, 0, 112, 2156, 39204}, 50] (* or *) Table[(1/5)*(Fibonacci[6n+3] - 12*Fibonacci[2n+1] + 10*(-1)^n), {n,0,25}] (* G. C. Greubel, Dec 09 2016 *)
  • PARI
    for(n=0,30, print1((1/5)*(fibonacci(6*n+3) - 12*fibonacci(2*n+1) + 10*(-1)^n), ", ")) \\ G. C. Greubel, Dec 21 2017
    

Formula

Let F(n) be the Fibonacci number A000045(n) and let L(n) be the Lucas number A000032(n).
a(n) = F(n)^2 * L(n+1)^2 * F(n-1) * L(n+2).
Unfactored form: a(n) = (1/5)*(F(6n+3) - 12*F(2n+1) + 10*(-1)^n).
Unfactored form: a(n) = F(2n+1)^3 - 3*F(2n+1) + 2*(-1)^n.
Summation form: a(n) = 4*Sum_{k=1..n} F(2k)^3 = 4 A163198(n) if n is even; a(n) = 4*Sum_{k=2..n} F(2k)^3 = 4 A163199(n) if n is odd. a(n) - 21 a(n-1) + 56 a(n-2) - 21 a(n-3) + a(n-4) = 200*(-1)^n.
a(n) - 20 a(n-1) + 35 a(n-2) + 35 a(n-3) - 20 a(n-4) + a(n-5) = 0.
G.f.: (112*x^2 - 84*x^3 + 4*x^4)/(1 - 20*x + 35*x^2 + 35*x^3 - 20*x^4 + x^5) = 4*x^2*(28 - 21*x + x^2)/((1 + x)*(1 - 3*x + x^2)*(1 - 18*x + x^2)).
a(n) - A163196(n) = 4*(-1)^n.

A163195 a(n) = (1/4)*F(n)^2 * L(n+1)^2 * F(n-1) * L(n+2), where F(n) and L(n) are the Fibonacci and Lucas numbers, respectively.

Original entry on oeis.org

0, 0, 28, 539, 9801, 176175, 3162160, 56744792, 1018249596, 18271762299, 327873509425, 5883451505855, 105574253853888, 1894453118539344, 33994581881622076, 610008020755286075, 10946149791725643705, 196420688230338021807, 3524626238354441796016, 63246851602149831726824
Offset: 0

Views

Author

Stuart Clary, Jul 24 2009

Keywords

Comments

Natural bilateral extension (brackets mark index 0): ..., 9800, 540, 27, 1, -1, [0], 0, 28, 539, 9801, 176175, ... This is A163197-reversed followed by A163195. That is, A163195(-n) = A163197(n-1).

References

  • Stuart Clary and Paul D. Hemenway, On sums of cubes of Fibonacci numbers, Applications of Fibonacci Numbers, Vol. 5 (St. Andrews, 1992), 123-136, Kluwer Acad. Publ., 1993. See equation (3).

Crossrefs

Programs

  • Magma
    [(1/4)*(Fibonacci(n)*Lucas(n+1))^2*(Fibonacci(n-1)*Lucas(n+2)): n in [0..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    a[n_Integer] := (1/4)*Fibonacci[n]^2 * LucasL[n+1]^2 * Fibonacci[n-1] * LucasL[n+2]
    LinearRecurrence[{20,-35,-35,20,-1}, {0,0,28,539,9801}, 50] (* or *) Table[(Fibonacci[6n+3] - 12*Fibonacci[2n+1] + 10*(-1)^n)/20, {n,1,25}] (* G. C. Greubel, Dec 09 2016 *)
  • PARI
    for(n=0,30, print1((fibonacci(6*n+3) - 12*fibonacci(2*n+1) + 10*(-1)^n)/20, ", ")) \\ G. C. Greubel, Dec 21 2017
    

Formula

Let F(n) be the Fibonacci number A000045(n) and let L(n) be the Lucas number A000032(n).
a(n) = (1/4)*F(n)^2 * L(n+1)^2 * F(n-1) * L(n+2).
a(n) = (1/20)*(F(6n+3) - 12*F(2n+1) + 10*(-1)^n).
a(n) = (1/4)(F(2n+1)^3 - 3*F(2n+1) + 2*(-1)^n).
a(n) = Sum_{k=1..n} F(2k)^3 = A163198(n) if n is even.
a(n) = Sum_{k=2..n} F(2k)^3 = A163199(n) if n is odd.
a(n) - 21 a(n-1) + 56 a(n-2) - 21 a(n-3) + a(n-4) = 50*(-1)^n.
a(n) - 20 a(n-1) + 35 a(n-2) + 35 a(n-3) - 20 a(n-4) + a(n-5) = 0.
G.f.: (28*x^2 - 21*x^3 + x^4)/(1 - 20*x + 35*x^2 + 35*x^3 - 20*x^4 + x^5) = x^2*(28 - 21*x + x^2)/((1 + x)*(1 - 3*x + x^2)*(1 - 18*x + x^2)).
a(n) - A163197(n) = (-1)^n.

A163197 a(n) = (1/4)* L(n)^2 * F(n+1)^2 * L(n-1) * F(n+2), where F(n) and L(n) are the Fibonacci and Lucas numbers, respectively.

Original entry on oeis.org

-1, 1, 27, 540, 9800, 176176, 3162159, 56744793, 1018249595, 18271762300, 327873509424, 5883451505856, 105574253853887, 1894453118539345, 33994581881622075, 610008020755286076, 10946149791725643704, 196420688230338021808, 3524626238354441796015, 63246851602149831726825
Offset: 0

Views

Author

Stuart Clary, Jul 24 2009

Keywords

Comments

Natural bilateral extension (brackets mark index 0): ..., 9801, 539, 28, 0, 0, [-1], 1, 27, 540, 9800, 176176, ... This is A163195-reversed followed by A163197. That is, A163197(-n) = A163195(n-1).

Crossrefs

Programs

  • Magma
    [(1/4)*(Lucas(n)*Fibonacci(n+1))^2*Lucas(n-1)*Fibonacci(n+2): n in [0..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    a[n_Integer] := (1/4)*LucasL[n]^2*Fibonacci[n+1]^2*LucasL[n-1]*Fibonacci[n+2]
    LinearRecurrence[{20,-35,-35,20,-1},{-1,1,27,540,9800}, 50] (* or *) Table[(1/20)*(Fibonacci[6*n+3] - 12*Fibonacci[2*n+1] - 10*(-1)^n),{n,0,25}] (* G. C. Greubel, Dec 09 2016 *)
  • PARI
    Vec(-(1 - 21*x + 28*x^2)/((1 + x)*(1 - 3*x + x^2)*(1 - 18*x + x^2)) + O(x^50)) \\ G. C. Greubel, Dec 09 2016
    
  • PARI
    for(n=0,30, print((1/20)*(fibonacci(6*n+3) - 12*fibonacci(2*n+1) - 10*(-1)^n), ", ")) \\ G. C. Greubel, Dec 21 2017
    

Formula

Let F(n) be the Fibonacci number A000045(n) and let L(n) be the Lucas number A000032(n).
a(n) = (1/4)*L(n)^2*F(n+1)^2*L(n-1)*F(n+2).
a(n) = (1/20)*(F(6n+3) - 12*F(2n+1) - 10*(-1)^n).
a(n) = (1/4)*(F(2n+1)^3 - 3*F(2n+1) - 2*(-1)^n).
a(n) = Sum_{k=2..n} F(2k)^3 = A163199(n) if n is even.
a(n) = Sum_{k=1..n} F(2k)^3 = A163198(n) if n is odd.
a(n) - 21 a(n-1) + 56 a(n-2) - 21 a(n-3) + a(n-4) = - 50*(-1)^n.
a(n) - 20 a(n-1) + 35 a(n-2) + 35 a(n-3) - 20 a(n-4) + a(n-5) = 0.
G.f.: (-1 + 21*x - 28*x^2)/(1 - 20*x + 35*x^2 + 35*x^3 - 20*x^4 + x^5) = -(1 - 21*x + 28*x^2)/((1 + x)*(1 - 3*x + x^2)*(1 - 18*x + x^2)).
A163195(n) - a(n) = (-1)^n.

A163199 Sum of the cubes of the first n even-indexed Fibonacci numbers, minus 1.

Original entry on oeis.org

-1, 0, 27, 539, 9800, 176175, 3162159, 56744792, 1018249595, 18271762299, 327873509424, 5883451505855, 105574253853887, 1894453118539344, 33994581881622075, 610008020755286075, 10946149791725643704, 196420688230338021807, 3524626238354441796015, 63246851602149831726824
Offset: 0

Views

Author

Stuart Clary, Jul 24 2009

Keywords

Comments

Natural bilateral extension (brackets mark index 0): ..., 9800, 539, 27, 0, -1, [-1], 0, 27, 539, 9800, 176175, ... This is A163199-reversed followed by A163199. That is, A163199(-n) = A163199(n-1).

Crossrefs

Programs

  • Mathematica
    a[n_Integer] := If[ n >= 0, Sum[ Fibonacci[2k]^3, {k, 1, n} ] - 1, -Sum[ Fibonacci[-2k]^3, {k, 1, -n - 1} ] - 1 ]
    Accumulate[Fibonacci[Range[0,40,2]]^3]-1 (* Harvey P. Dale, Jan 03 2016 *)
    LinearRecurrence[{22,-77,77,-22,1},{-1,0,27,539,9800},50] (* or *) Table[(1/20)*(F(6n+3) - 12*F(2n+1) - 10),{n,0,25}] (* G. C. Greubel, Dec 09 2016 *)
  • PARI
    Vec(-(1 - 22*x + 50*x^2 - 22*x^3 + x^4)/((1 - x)*(1 - 3*x + x^2 )*(1 - 18*x + x^2)) + O(x^50)) \\ G. C. Greubel, Dec 09 2016

Formula

Let F(n) be the Fibonacci number A000045(n) and let L(n) be the Lucas number A000032(n).
a(n) = Sum_{k=1..n} F(2k)^3 - 1.
a(n) = Sum_{k=2..n} F(2k)^3 for n > 0.
a(n) = A163198(n) - 1.
a(n) = (1/20)*(F(6n+3) - 12*F(2n+1) - 10).
a(n) = (1/4)*(F(2n+1)^3 - 3*F(2n+1) - 2).
a(n) = (1/4)*L(n)^2*F(n+1)^2*L(n-1)*F(n+2) = A163197(n) if n is even.
a(n) = (1/4)*F(n)^2*L(n+1)^2*F(n-1)*L(n+2) = A163195(n) if n is odd.
a(n) - 21 a(n-1) + 56 a(n-2) - 21 a(n-3) + a(n-4) = -8.
a(n) - 22 a(n-1) + 77 a(n-2) - 77 a(n-3) + 22 a(n-4) - a(n-5) = 0.
G.f.: (-1 + 22*x - 50*x^2 + 22*x^3 - x^4)/(1 - 22*x + 77*x^2 - 77*x^3 + 22*x^4 - x^5) = -(1 - 22*x + 50*x^2 - 22*x^3 + x^4)/((1 - x)*(1 - 3*x + x^2 )*(1 - 18*x + x^2)).
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