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 1-10 of 335 results. Next

A003263 Number of representations of n as a sum of distinct Lucas numbers 1, 3, 4, 7, 11, ... (A000204).

Original entry on oeis.org

1, 0, 1, 2, 1, 0, 2, 2, 0, 1, 3, 2, 0, 2, 3, 1, 0, 3, 3, 0, 2, 4, 2, 0, 3, 3, 0, 1, 4, 3, 0, 3, 5, 2, 0, 4, 4, 0, 2, 5, 3, 0, 3, 4, 1, 0, 4, 4, 0, 3, 6, 3, 0, 5, 5, 0, 2, 6, 4, 0, 4, 6, 2, 0, 5, 5, 0, 3, 6, 3, 0, 4, 4, 0, 1, 5, 4, 0, 4, 7, 3, 0, 6, 6, 0, 3, 8, 5, 0, 5, 7, 2, 0, 6, 6, 0, 4, 8, 4, 0, 6, 6, 0, 2, 7
Offset: 1

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Author

Keywords

References

  • A. Brousseau, Fibonacci and Related Number Theoretic Tables. Fibonacci Association, San Jose, CA, 1972, p. 58.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Mathematica
    n1 = 10; n2 = LucasL[n1]; Product[1 + x^LucasL[n], {n, 1, n1}] + O[x]^n2 // CoefficientList[#, x]& // Rest (* Jean-François Alcover, Feb 17 2017, after Joerg Arndt *)
  • PARI
    L(n)=fibonacci(n+1) + fibonacci(n-1);
    N = 66;  x = 'x + O('x^N);
    gf = prod(n=1, 11, 1 + x^L(n) );
    Vec(gf) \\ Joerg Arndt, Jul 14 2013

Formula

G.f.: Product_{n>=1} (1 + x^L(n)) where L(n) = A000204(n). - Joerg Arndt, Jul 14 2013

Extensions

More terms from James Sellers, May 29 2000

A054770 Numbers that are not the sum of distinct Lucas numbers 1,3,4,7,11, ... (A000204).

Original entry on oeis.org

2, 6, 9, 13, 17, 20, 24, 27, 31, 35, 38, 42, 46, 49, 53, 56, 60, 64, 67, 71, 74, 78, 82, 85, 89, 93, 96, 100, 103, 107, 111, 114, 118, 122, 125, 129, 132, 136, 140, 143, 147, 150, 154, 158, 161, 165, 169, 172, 176, 179, 183, 187, 190, 194, 197, 201, 205, 208, 212
Offset: 1

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Author

Antreas P. Hatzipolakis (xpolakis(AT)otenet.gr), May 28 2000

Keywords

Comments

Alternatively, Lucas representation of n includes L_0 = 2. - Fred Lunnon, Aug 25 2001
Conjecture: this is the sequence of numbers for which the base phi representation includes phi itself, where phi = (1 + sqrt(5))/2 = the golden ratio. Example: let r = phi; then 6 = r^3 + r + r^(-4). - Clark Kimberling, Oct 17 2012
This conjecture is proved in my paper 'Base phi representations and golden mean beta-expansions', using the formula by Wilson/Agol/Carlitz et al. - Michel Dekking, Jun 25 2019
Numbers whose minimal Lucas representation (A130310) ends with 1. - Amiram Eldar, Jan 21 2023

Crossrefs

Complement of A063732.

Programs

  • Magma
    [Floor(n*(Sqrt(5)+5)/2)-1: n in [1..60]]; // Vincenzo Librandi, Oct 30 2018
    
  • Maple
    A054770 := n -> floor(n*(sqrt(5)+5)/2)-1;
  • Mathematica
    Complement[Range[220],Total/@Subsets[LucasL[Range[25]],5]] (* Harvey P. Dale, Feb 27 2012 *)
    Table[Floor[n (Sqrt[5] + 5) / 2] - 1, {n, 60}] (* Vincenzo Librandi, Oct 30 2018 *)
  • PARI
    a(n)=floor(n*(sqrt(5)+5)/2)-1
    
  • Python
    from math import isqrt
    def A054770(n): return (n+isqrt(5*n**2)>>1)+(n<<1)-1 # Chai Wah Wu, Aug 17 2022

Formula

a(n) = floor(((5+sqrt(5))/2)*n)-1 (conjectured by David W. Wilson; proved by Ian Agol (iagol(AT)math.ucdavis.edu), Jun 08 2000)
a(n) = A000201(n) + 2*n - 1. - Michel Dekking, Sep 07 2017
G.f.: x*(x+1)/(1-x)^2 + Sum_{i>=1} (floor(i*phi)*x^i), where phi = (1 + sqrt(5))/2. - Iain Fox, Dec 19 2017
Ian Agol tells me that David W. Wilson's formula is proved in the Carlitz, Scoville, Hoggatt paper 'Lucas representations'. See Equation (1.12), and use A(A(n))+n = B(n)+n-1 = A(n)+2*n-1, the well known formulas for the lower Wythoff sequence A = A000201, and the upper Wythoff sequence B = A001950. - Michel Dekking, Jan 04 2018

Extensions

More terms from James Sellers, May 28 2000

A090946 Non-Lucas numbers: complement of A000204.

Original entry on oeis.org

0, 2, 5, 6, 8, 9, 10, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79
Offset: 1

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Author

N. J. A. Sloane, Feb 28 2004

Keywords

Crossrefs

Programs

  • Maple
    L[1]:=1: L[2]:=3: for n from 3 to 10 do L[n]:=L[n-1]+L[n-2] od: A:={seq(L[n],n=1..10)}: B:={seq(n,n=0..L[10])}: C:=B minus A; # Emeric Deutsch, Dec 14 2004
  • Mathematica
    Complement[Range[0,100],LucasL[Range[10]]] (* Harvey P. Dale, Mar 21 2012 *)
  • Python
    def A090946(n):
        if n == 1: return 0
        def f(x):
            if x<=2: return n
            a, b, c = 1, 3, 0
            while b<=x:
                a, b = b, a+b
                c += 1
            return n+c
        m, k = n, f(n)
        while m != k: m, k = k, f(k)
        return m # Chai Wah Wu, Sep 10 2024

Formula

a(n) = A057854(n-2), n>2. - R. J. Mathar, Jan 29 2019

Extensions

More terms from Emeric Deutsch, Dec 14 2004
Offset corrected by Michel Marcus, Aug 15 2017

A067979 Triangle read by rows of incomplete convolutions of Lucas numbers L(n+1) = A000204(n+1), n>=0.

Original entry on oeis.org

1, 3, 6, 4, 13, 17, 7, 19, 31, 38, 11, 32, 48, 69, 80, 18, 51, 79, 107, 140, 158, 29, 83, 127, 176, 220, 274, 303, 47, 134, 206, 283, 360, 432, 519, 566, 76, 217, 333, 459, 580, 706, 822, 963, 1039, 123, 351, 539, 742, 940, 1138, 1341, 1529, 1757, 1880, 199, 568, 872, 1201, 1520, 1844, 2163, 2492, 2796, 3165, 3364
Offset: 0

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Author

Wolfdieter Lang, Feb 15 2002

Keywords

Comments

The diagonals d>=0 (d=0: main diagonal) give convolutions of Lucas numbers L(n+1) := A000204(n+1), n>=0, with those with d-shifted index: a(d+n,d) = Sum_{k=0..n} L(k+1)*L(d+n+1-k).
The diagonals give A004799(n-1), A067980-7 for d=n-m= 0..8, respectively. Row sums give A067989.
The row polynomials p(n,x) := sum(a(n,m)*x^m,m=0..n) are generated by A(x*z)*(A(z)-x*A(x*z))/(1-x), with A(x) := (1+2*x)/(1-x-x^2) (g.f. Lucas L(n+1), n>=0).

Examples

			Triangle begins:
  {1};
  {3,6};
  {4,13,17};     p(2,x) = 4+13*x+17*x^2
  {7,19,31,38};
  ...
		

Crossrefs

Cf. A067990 (triangle with rows read backwards).

Programs

  • Mathematica
    Table[Sum[LucasL[k + 1] LucasL[n - k + 1], {k, 0, m}], {n, 0, 10}, {m, 0, n}] // Flatten (* Michael De Vlieger, Apr 11 2016 *)
  • PARI
    for(n=0,10, for(k=0,n, print1(sum(m=0,k,(fibonacci(m+2) + fibonacci(m))*(fibonacci(n-m+2) + fibonacci(n-m))), ", "))) \\ G. C. Greubel, Dec 17 2017

Formula

a(n, m) = Sum_{k=0..m} L(k+1)*L(n-k+1), n>=m>=0, else 0.
a(n, m) = (m+1)*L(n-m+1)*F(m) + ((m+1)*L(n-m+1) + m*L(n-m))*F(m+1), n>=m>=0, with F(n) := A000045(n) (Fibonacci) and L(n) := A000032(n) (Lucas).
G.f. for diagonals d= n-m>=0: (x^d)*(L(d+1)+L(d)*x)*(1-2*x)/(1-x-x^2)^2.
a(n, m) = -(-1)^m*F(n-2*m-1) + m*L(n+2)+F(n+3), with F(-n) = (-1)^(n+1) * F(n), hence a(n, m) = -5*A067330(n, m)+2*(m+1)*L(n+2), n>=m>=0. - Ehren Metcalfe, Apr 11 2016

A203803 G.f.: exp( Sum_{n>=1} A000204(n)^3 * x^n/n ) where A000204 is the Lucas numbers.

Original entry on oeis.org

1, 1, 14, 35, 205, 744, 3414, 13926, 60060, 252330, 1072902, 4537272, 19234463, 81452015, 345084970, 1461714517, 6192083147, 26229794928, 111111714300, 470675847900, 1993816532280, 8445939457380, 35777578796220, 151556246864400, 642002579853325, 2719566542567917
Offset: 0

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Author

Paul D. Hanna, Jan 06 2012

Keywords

Comments

More generally, exp(Sum_{k>=1} A000204(k)^(2*n+1) * x^k/k) = Product_{k=0..n} 1/(1 - (-1)^(n-k)*A000204(2*k+1)*x - x^2)^binomial(2*n+1,n-k).

Examples

			G.f.: A(x) = 1 + x + 14*x^2 + 35*x^3 + 205*x^4 + 744*x^5 + 3414*x^6 +...
where
log(A(x)) = x + 3^3*x^2/2 + 4^3*x^3/3 + 7^3*x^4/4 + 11^3*x^5/5 + 18^3*x^6/6 + 29^3*x^7/7 + 47^3*x^8/8 +...+ Lucas(n)^3*x^n/n +...
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[1/((1 + x - x^2)^3*(1 - 4*x - x^2)), {x, 0, 50}], x] (* G. C. Greubel, Dec 24 2017 *)
  • PARI
    /* Subroutine used in PARI programs below: */
    {Lucas(n)=fibonacci(n-1)+fibonacci(n+1)}
    
  • PARI
    {a(n)=polcoeff(exp(sum(k=1, n, Lucas(k)^3*x^k/k)+x*O(x^n)), n)}
    
  • PARI
    {a(n,m=1)=polcoeff(prod(k=0,m, 1/(1 - (-1)^(m-k)*Lucas(2*k+1)*x - x^2+x*O(x^n))^binomial(2*m+1,m-k)),n)}

Formula

G.f.: 1/( (1+x-x^2)^3 * (1-4*x-x^2) ).
G.f.: 1/Product_{n>=1} (1 - Lucas(n)*x^n + (-1)^n*x^(2*n))^A203853(n) where A203853(n) = (1/n)*Sum_{d|n} moebius(n/d)*Lucas(d)^2.

A203804 G.f.: exp( Sum_{n>=1} A000204(n)^4 * x^n/n ) where A000204 is the Lucas numbers.

Original entry on oeis.org

1, 1, 41, 126, 1526, 7854, 63629, 400789, 2870629, 19254504, 133376760, 909578760, 6249172910, 42785312510, 293403088510, 2010553849020, 13781960765020, 94458627485820, 647442212896270, 4437595353800270, 30415849505902910, 208472981440853160, 1428896115173689560
Offset: 0

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Author

Paul D. Hanna, Jan 06 2012

Keywords

Comments

More generally, exp(Sum_{k>=1} A000204(k)^(2*n) * x^k/k) = 1/(1 - (-1)^n*x)^binomial(2*n,n) * Product_{k=1..n} 1/(1 - (-1)^(n-k)*A000204(2*k)*x + x^2)^binomial(2*n,n-k).

Examples

			G.f.: A(x) = 1 + x + 41*x^2 + 126*x^3 + 1526*x^4 + 7854*x^5 + 63629*x^6 +...
where
log(A(x)) = x + 3^4*x^2/2 + 4^4*x^3/3 + 7^4*x^4/4 + 11^4*x^5/5 + 18^4*x^6/6 + 29^4*x^7/7 + 47^4*x^8/8 +...+ Lucas(n)^4*x^n/n +...
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[1/((1 - x)^6*(1 + 3*x + x^2)^4*(1 - 7*x + x^2)), {x, 0, 50}], x] (* G. C. Greubel, Dec 24 2017 *)
  • PARI
    /* Subroutine used in PARI programs below: */
    {Lucas(n)=fibonacci(n-1)+fibonacci(n+1)}
    
  • PARI
    {a(n)=polcoeff(exp(sum(k=1, n, Lucas(k)^4*x^k/k)+x*O(x^n)), n)}
    
  • PARI
    {a(n,m=2)=polcoeff(1/(1 - (-1)^m*x+x*O(x^n))^binomial(2*m,m) * prod(k=1,m,1/(1 - (-1)^(m-k)*Lucas(2*k)*x + x^2+x*O(x^n))^binomial(2*m,m-k)),n)}

Formula

G.f.: 1/( (1-x)^6 * (1+3*x+x^2)^4 * (1-7*x+x^2) ).
G.f.: 1/Product_{n>=1} (1 - Lucas(n)*x^n + (-1)^n*x^(2*n))^A203854(n) where A203854(n) = (1/n)*Sum_{d|n} moebius(n/d)*Lucas(d)^3.

A101032 Table (read by rows) giving the coefficients of sum formulas of n-th Lucas numbers (A000204). The k-th row (k>=1) contains T(i,k) for i=1 to k, where k=[2*n+1+(-1)^(n-1)]/4 and T(i,k) satisfies L(n) = Sum_{i=1..k} T(i,k) * n^(k-i) / (k-1)!.

Original entry on oeis.org

1, 1, 1, 1, -1, 2, 1, -6, 17, 6, 1, -14, 83, -142, 24, 1, -25, 265, -1235, 2314, 120, 1, -39, 655, -5565, 24184, -41556, 720, 1, -56, 1372, -18200, 137599, -556304, 944628, 5040, 1, -76, 2562, -48664, 560049, -3884524, 15021068, -24875376, 40320, 1, -99, 4398, -113022, 1829793, -19043451
Offset: 1

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Author

André F. Labossière, Nov 30 2004

Keywords

Examples

			L(13)=521; substituting n=13 in the formula of the k-th row we obtain k=7 and the coefficients
T(i,7) will be the following: 1,-39,655,-5565,24184,-41556,720,
=> L(13) = [13^6-39*13^5+655*13^4-5565*13^3+24184*13^2-41556*13+720]/6! = 521.
		

Crossrefs

A127210 a(n) = 3^n*Lucas(n), where Lucas = A000204.

Original entry on oeis.org

3, 27, 108, 567, 2673, 13122, 63423, 308367, 1495908, 7263027, 35252253, 171124002, 830642283, 4032042867, 19571909148, 95004113247, 461159522073, 2238515585442, 10865982454983, 52744587633927, 256027604996628, 1242784103695227, 6032600756055333, 29282859201423042
Offset: 1

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

  • Magma
    [3^n*Lucas(n): n in [1..30]]; // Vincenzo Librandi, Aug 07 2015
  • Mathematica
    Table[3^n Tr[MatrixPower[{{1, 1}, {1, 0}}, x]], {x, 1, 20}]
    Table[3^n LucasL[n], {n, 25}] (* Vincenzo Librandi, Aug 07 2015 *)
  • PARI
    lucas(n) = fibonacci(n-1) + fibonacci(n+1);
    vector(30, n, 3^n*lucas(n)) \\ Michel Marcus, Aug 07 2015
    

Formula

a(n) = Trace of matrix [({3,3},{3,0})^n] = 3^n * Trace of matrix [({1,1},{1,0})^n].
From R. J. Mathar, Oct 27 2008: (Start)
a(n) = 3*a(n-1) + 9*a(n-2).
G.f.: 3*x*(1 + 6*x)/(1 - 3*x - 9*x^2).
a(n) = 3*A099012(n) +18*A099012(n-1). (End)

Extensions

More terms from Michel Marcus, Aug 07 2015

A127212 a(n) = 5^n*Lucas(n), where Lucas = A000204.

Original entry on oeis.org

5, 75, 500, 4375, 34375, 281250, 2265625, 18359375, 148437500, 1201171875, 9716796875, 78613281250, 635986328125, 5145263671875, 41625976562500, 336761474609375, 2724456787109375, 22041320800781250, 178318023681640625
Offset: 1

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

  • Magma
    [5^n*Lucas(n): n in [1..30]]; // G. C. Greubel, Dec 18 2017
  • Mathematica
    Table[5^n Tr[MatrixPower[{{1, 1}, {1, 0}}, x]], {x, 1, 20}]
    Table[5^n*LucasL[n], {n,1,50}] (* G. C. Greubel, Dec 18 2017 *)
    LinearRecurrence[{5,25},{5,75},20] (* Harvey P. Dale, Jan 11 2024 *)
  • PARI
    x='x+O('x^30); Vec(-5*x*(10*x+1)/(25*x^2+5*x-1)) \\ G. C. Greubel, Dec 18 2017
    

Formula

a(n) = Trace of matrix [({5,5},{5,0})^n].
a(n) = 5^n * Trace of matrix [({1,1},{1,0})^n].
From Colin Barker, Sep 02 2013: (Start)
a(n) = 5*a(n-1) + 25*a(n-2).
G.f.: -5*x*(10*x+1)/(25*x^2+5*x-1). (End)

A127213 a(n) = 6^n*Lucas(n), where Lucas = A000204.

Original entry on oeis.org

6, 108, 864, 9072, 85536, 839808, 8118144, 78941952, 765904896, 7437339648, 72196614144, 700923912192, 6804621582336, 66060990332928, 641332318961664, 6226189565755392, 60445100877152256, 586813429630107648
Offset: 1

Views

Author

Artur Jasinski, Jan 09 2007

Keywords

Crossrefs

Programs

  • Magma
    [6^n*Lucas(n): n in [1..30]]; // G. C. Greubel, Dec 18 2017
  • Mathematica
    Table[6^n Tr[MatrixPower[{{1, 1}, {1, 0}}, x]], {x, 1, 20}]
    Table[6^n*LucasL[n], {n,1,50}] (* G. C. Greubel, Dec 18 2017 *)
    LinearRecurrence[{6,36},{6,108},20] (* Harvey P. Dale, Jan 20 2024 *)
  • PARI
    x='x+O('x^30); Vec(-6*x*(12*x+1)/(36*x^2+6*x-1)) \\ G. C. Greubel, Dec 18 2017
    

Formula

a(n) = Trace of matrix [({6,6},{6,0})^n].
a(n) = 6^n * Trace of matrix [({1,1},{1,0})^n].
From Colin Barker, Sep 02 2013: (Start)
a(n) = 6*a(n-1) + 36*a(n-2).
G.f.: -6*x*(12*x+1)/(36*x^2+6*x-1). (End)
Showing 1-10 of 335 results. Next