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.

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A166169 a(n) = Lucas(n^2) = A000204(n^2) for n >= 1.

Original entry on oeis.org

1, 7, 76, 2207, 167761, 33385282, 17393796001, 23725150497407, 84722519070079276, 792070839848372253127, 19386725908489881939795601, 1242282009792667284144565908482, 208406472252232726621841472637412401
Offset: 1

Views

Author

Paul D. Hanna, Oct 08 2009

Keywords

Crossrefs

Programs

  • Magma
    [ Lucas(n^2) : n in [1..50]]; // Vincenzo Librandi, Apr 14 2011
  • Mathematica
    Table[LucasL[n^2], {n, 1, 10}] (* G. C. Greubel, May 06 2016 *)
  • PARI
    a(n)=fibonacci(n^2-1)+fibonacci(n^2+1)
    

Formula

Logarithmic derivative of A166168.
a(n) = ((1 + sqrt(5))/2)^(n^2) + ((1 - sqrt(5))/2)^(n^2).
a(n) = Fibonacci(n^2 - 1) + Fibonacci(n^2 + 1).

A204291 G.f.: Sum_{n>=1} moebius(n)*x^n/(1 - Lucas(n)*x^n + (-1)^n*x^(2*n)), where Lucas(n) = A000204(n).

Original entry on oeis.org

1, 0, 1, 0, 4, -3, 12, 0, 17, -10, 88, -54, 232, -28, 184, 0, 1596, -969, 4180, -1230, 4632, -198, 28656, -17388, 60020, -520, 98209, -23604, 514228, -461932, 1346268, 0, 1722688, -3570, 6672168, -5598882, 24157816, -9348, 31351552, -18606210, 165580140
Offset: 1

Views

Author

Paul D. Hanna, Jan 14 2012

Keywords

Comments

Compare g.f. to the identity: x = Sum_{n>=1} moebius(n)*fibonacci(n)*x^n/(1 - Lucas(n)*x^n + (-1)^n*x^(2*n)).

Examples

			G.f.: A(x) = x + x^3 + 4*x^5 - 3*x^6 + 12*x^7 + 17*x^9 - 10*x^10 + 88*x^11 +...
where A(x) = x/(1-x-x^2) - x^2/(1-3*x^2+x^4) - x^3/(1-4*x^3-x^6) - x^5/(1-11*x^5-x^10) + x^6/(1-18*x^6+x^12) +...+ moebius(n)*x^n/(1 - Lucas(n)*x^n + (-1)^n*x^(2*n)) +...
		

Crossrefs

Cf. A203847, A000204 (Lucas), A000045, A008683.

Programs

  • Maple
    with(numtheory): seq(add(mobius(d)*combinat[fibonacci](n)/combinat[fibonacci](d), d in divisors(n)), n=1..60); # Ridouane Oudra, Apr 09 2025
  • PARI
    {Lucas(n)=fibonacci(n-1)+fibonacci(n+1)}
    {a(n)=polcoeff(sum(m=1,n,moebius(m)*x^m/(1-Lucas(m)*x^m+(-1)^m*x^(2*m)+x*O(x^n))),n)}

Formula

a(k) = 0 iff k = 2^n for n>=1.
a(n) = Fibonacci(n) * Sum_{d|n} mu(d)/Fibonacci(d). - Ridouane Oudra, Apr 09 2025

A225528 a(n) = sigma(n)*Lucas(n) where Lucas(n) = A000204(n) and sigma(n) = A000203(n) is the sum of divisors of n.

Original entry on oeis.org

1, 9, 16, 49, 66, 216, 232, 705, 988, 2214, 2388, 9016, 7294, 20232, 32736, 68417, 64278, 225342, 186980, 635334, 783232, 1425708, 1537896, 6220920, 5200591, 11400606, 17568160, 39796232, 34495530, 133955856, 96331168, 306863361, 378297408, 688610322, 990395472, 3038060662
Offset: 1

Views

Author

Paul D. Hanna, May 09 2013

Keywords

Examples

			L.g.f.: L(x) = x + 9*x^2/2 + 16*x^3/3 + 49*x^4/4 + 66*x^5/5 + 216*x^6/6 +...
which is equivalent to:
L(x) = x + 3*3*x^2/2 + 4*4*x^3/3 + 7*7*x^4/4 + 6*11*x^5/5 + 12*18*x^6/6 + 8*29*x^7/7 + 15*47*x^8/8 +...+ sigma(n)*Lucas(n)*x^n/n +...
where exponentiation yields the g.f. of A156234:
exp(L(x)) = 1 + x + 5*x^2 + 10*x^3 + 30*x^4 + 63*x^5 + 170*x^6 + 355*x^7 +...+ A156234(n)*x^n +...
and equals the product:
exp(L(x)) = 1/((1-x-x^2) * (1-3*x^2+x^4) * (1-4*x^3-x^6) * (1-7*x^4+x^8) * (1-11*x^5-x^10) * (1-18*x^6+x^12) *...* (1 - Lucas(n)*x^n + (-x^2)^n) *...).
		

Crossrefs

Programs

  • PARI
    {a(n)=sigma(n)*(fibonacci(n-1)+fibonacci(n+1))}
    for(n=1,40,print1(a(n),", "))
    
  • PARI
    {Lucas(n)=fibonacci(n-1)+fibonacci(n+1)}
    {a(n)=n*polcoeff(sum(m=1, n, -log(1 - Lucas(m)*x^m + (-1)^m*x^(2*m) +x*O(x^n))), n)}
    for(n=1,40,print1(a(n),", "))

Formula

L.g.f.: Sum_{n>=1} -log(1 - Lucas(n)*x^n + (-1)^n*x^(2*n)) = Sum_{n>=1} a(n)*x^n/n.
Logarithmic derivative of A156234.

A294203 Number of partitions of n into distinct Lucas parts (A000204) greater than 1.

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Oct 24 2017

Keywords

Comments

Convolution of the sequences A003263 and A033999.
Positions of 0: 1, 2, 5, 6, 8, 9, 12, 13, ... = A287775(n) - 1 (conjecture).
From Michel Dekking, Dec 30 2017: (Start)
Proof of the 'positions of 0' conjecture: let (z(n))=1,2,5,6,8,9,12,... be the positions of 0. The crucial observation is that if a number n is the sum of distinct Lucas parts greater than 1, then n+1 is a sum of Lucas parts. This implies that (z(2n))=2,6,9,13,... is the sequence of numbers A054770 that are not a sum of Lucas numbers. We see there that Ian Agol proved that b(n):=A054770(n)=floor(phi*n)+2n-1. But then the sequence of first differences (b(n+1)-b(n)) equals the Fibonacci word on the alphabet {4,3}, yielding that (z(2n)-z(2n-1)) equals the Fibonacci word on {3,2}, and we already know that z(2n+1)-z(2n)=1 for all n. On the other hand, A287775 has the same first difference sequence given by A108103. Since A287775(1)=2, the conjecture follows. (End)
Positions of 1: 0, 3, 4, 10, 15, 28, 44, 75, ... = A001350(n+1) - 1 (conjecture).

Examples

			a(7) = 2 because we have [7] and [4, 3].
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[Product[1 + x^LucasL[k], {k, 2, 15}], {x, 0, 100}], x]

Formula

G.f.: Product_{k>=2} (1 + x^Lucas(k)).

A061189 Triangle of coefficients of polynomials (rising powers) useful for convolutions of A000204(n+1), n >= 0 (Lucas numbers).

Original entry on oeis.org

1, 2, 0, -10, 15, 25, 30, 475, 450, 125, 6000, 8500, 6250, 5000, 1250, 96000, 146250, 189375, 159375, 65625, 9375, 180000, 5355000, 8881250, 5578125, 2515625, 721875, 78125, 44100000, 254700000, 341775000
Offset: 0

Views

Author

Wolfdieter Lang, Apr 20 2001

Keywords

Comments

The row polynomials pL2(n,x) := Sum_{m=0..n} a(n,m)*x^m and pL1(n,x) := Sum_{m=0..n} A061188(n,m)*x^m appear in the k-fold convolution of the Lucas numbers L(n+1) = A000204(n+1) = A000032(n+1), n >= 0, as follows: L(k; n) := A060922(n+k,k) = (pL1(k,n)*L(n+2)+pL2(k,n)*L(n+1))/(k!*5^k).

Examples

			Triangle begins:
  {1};
  {2,0};
  {-10,15,25};
  {30,475,450,125};
  ...;
pL2(2,n) = 5*(-2+3*n+5*n^2) = 5*(1+n)*(-2+5*n).
L(2; n) := A060922(n+2,2) = A060929(n) = (1+n)*((4+5*n)*L(n+2)+(-2+5*n)*L(n+1))/(2*5).
		

Crossrefs

Cf. A061188(n, m) (companion triangle), A060922(n, m) (Lucas convolution triangle).

A067980 Convolution of L(n+1) := A000204(n+1) (Lucas), n>=0, with L(n+2), n>=0.

Original entry on oeis.org

3, 13, 31, 69, 140, 274, 519, 963, 1757, 3165, 5642, 9972, 17499, 30521, 52955, 91461, 157336, 269702, 460863, 785295, 1334713, 2263293, 3829846, 6468264, 10905075, 18355429, 30849559, 51776133, 86785892
Offset: 0

Views

Author

Wolfdieter Lang, Feb 15 2002

Keywords

Comments

Second diagonal of triangle A067979. Second column of triangle A067990.

Formula

a(n)= sum(L(k+1)*L(n+2-k), k=0..n) = (4*n+3)*F(n+1)+3*(n+1)*F(n), with F(n) := A000045(n) (Fibonacci).
G.f.: (3+x)*(1+2*x)/(1-x-x^2)^2.

A083564 a(n) = L(n)*L(2n), where L(n) are the Lucas numbers (A000204).

Original entry on oeis.org

3, 21, 72, 329, 1353, 5796, 24447, 103729, 439128, 1860621, 7880997, 33385604, 141421803, 599075421, 2537719272, 10749959329, 45537545553, 192900159396, 817138154247, 3461452823129, 14662949371128, 62113250430021
Offset: 1

Views

Author

Gary W. Adamson, Jun 12 2003

Keywords

Comments

a(n+1)/a(n) -> (phi)^3 = ((1 + sqrt(5))/2)^3 = 4.236067...

Examples

			a(4) = Lucas(4)*Lucas(8) = 7*47 = 329.
		

Crossrefs

Third row of array A028412.

Programs

Formula

From Benoit Cloitre, Aug 30 2003: (Start)
a(n) = 3*a(n-1) + 6*a(n-2) - 3*a(n-3) - a(n-4);
a(n) = Fibonacci(4*n)/Fibonacci(n) = A000045(4*n)/A000045(n). (End)
a(n) = Lucas(3*n) + (-1)^n*Lucas(n).
From R. J. Mathar, Oct 27 2008: (Start)
G.f.: x*(3+12*x-9*x^2-4*x^3)/((1+x-x^2)*(1-4*x-x^2)).
a(n) = A061084(n+1) + 2*A001077(n). (End)
a(n) = (1+phi)^n + (-phi)^n + (2*phi+1)^n + (3-2*phi)^n, phi = (1+sqrt(5))/2. - Gary Detlefs, Dec 09 2012

A085292 Product of Lucas (A000204) and a Pell companion series (A001333).

Original entry on oeis.org

1, 9, 28, 119, 451, 1782, 6931, 27119, 105868, 413649, 1615681, 6311522, 24654241, 96306849, 376200748, 1469546399, 5740457491, 22423834422, 87593763331, 342165736199, 1336595027068, 5221113899769, 20395130698081, 79669083012482
Offset: 1

Views

Author

Gary W. Adamson, Jun 24 2003

Keywords

Crossrefs

Programs

  • Mathematica
    L[0] = 2; L[1] = 1; L[n] = L[n - 1] + L[n - 2]; P[0] = P[1] = 1; P[n_] := P[n] = 2P[n - 1] + P[n - 2]; Table[ L[n]P[n], {n, 1, 24}]
    With[{nn=30},Rest[LinearRecurrence[{2,1},{1,1},nn]LucasL[Range[0,nn-1]]]] (* Harvey P. Dale, Apr 20 2012 *)
    LinearRecurrence[{2, 7, 2, -1},{1, 9, 28, 119},24] (* Ray Chandler, Aug 03 2015 *)

Formula

a(n) = A000204(n) * A001333(n).
a(n) = 2*a(n-1)+7*a(n-2)+2*a(n-3)-a(n-4). G.f.: -x*(2*x^3-3*x^2-7*x-1) / (x^4-2*x^3-7*x^2-2*x+1). - Colin Barker, Oct 15 2013
2* A085292(n) = A085293(n).

Extensions

Edited and extended by Robert G. Wilson v, Jun 24 2003

A113910 Integers of the form (Lucas(i+1) - 2*A006206(i+2))/(A006206(i+2) - A006206(i)), i > 2; Lucas = A000204.

Original entry on oeis.org

3, 7, 5, 9, 11, 17, 29, 41, 59, 71, 101, 107, 137, 149, 179, 191, 197, 227, 239, 269, 281, 311, 347, 419, 431, 461, 521, 569, 599, 617, 641, 659, 809, 821, 827, 857, 881, 1019, 1031, 1049, 1061, 1091, 1151, 1229, 1277, 1289, 1301, 1319, 1427, 1451, 1481, 1487
Offset: 1

Views

Author

Creighton Dement, Jan 29 2006

Keywords

Comments

Let p and p+2 be twin primes. Then Lucas(p) = 1 + p*A006206(p) and Lucas(p+2) = 1 + (p+2)*A006206(p+2). It follows from Lucas(n) + Lucas(n+1) = Lucas(n+2) that p = (Lucas(p+1) - 2*A006206(p+2))/(A006206(p+2) - A006206(p))
For i = 3, 4, 5, 6, 7, 8, 9, 10, 11: ((Lucas(i+1) - 2*A006206(i+2))/(A006206(i+2) - A006206(i))) = (3, 7, 5, 19/3, 31/4, 9, 87/10, 149/14, 11, 135/11, 663/50, 1094/77, 1787/120, 2939/181, 17, 7849/434, 12799/672, 20894/1041, 34031/1622, 55469/2514, 45131/1962, 146921/6115, 238915/9554, 194252/7465, 631347/23386, 1025917/36617, 29, 2706059/90178, 4393211/141710, 3565643/111405, 11573003/350702). - Creighton Dement, Jan 31 2006

Crossrefs

Programs

  • Maple
    # First 63 Terms with(combinat): with(numtheory): A006206 := proc(n) local sum; sum := 0; for d in divisors(n) do sum := sum + mobius(n/d)*(fibonacci(d+1)+fibonacci(d-1)) od; RETURN(sum/n); end; A000204 := n->fibonacci(n+1)+fibonacci(n-1); T := n -> (A000204(n+1) - 2*A006206(n+2))/(A006206(n+2)-A006206(n)); A113910 := []: for i from 3 by 1 to 2000 do if is(T(i) = floor(T(i))) then A113910 := [op(A113910), T(i)]; fi: od: A113910; # Creighton Dement, Jan 15 2009

Formula

It is conjectured that a(n+4) = A001359(n+2) for all n.

Extensions

Extended and Maple definition by Creighton Dement, Jan 15 2009

A151558 Decimal expansion of the Lucas nested (A000204) radical.

Original entry on oeis.org

1, 8, 4, 0, 7, 6, 8, 3, 2, 8, 1, 4, 6, 0, 8, 2, 6, 8, 9, 8, 2, 0, 5, 7, 4, 5, 7, 7, 7, 4, 3, 5, 5, 7, 7, 8, 8, 6, 2, 1, 0, 6, 0, 3, 8, 7, 7, 7, 2, 1, 5, 4, 1, 6, 0, 5, 0, 8, 4, 9, 0, 2, 5, 0, 0, 4, 7, 8, 5, 1, 7, 4, 0, 5, 5, 6, 3, 4, 7, 0, 7, 7, 8, 5, 8, 9, 6, 0, 4, 5, 7, 0, 8, 6, 5, 1, 7, 2, 7, 8, 6, 1, 9, 5, 1
Offset: 1

Views

Author

Keywords

Comments

Analog of A105817 for the Lucas numbers (A000204).

Examples

			1.840768328146082689820574577743557788621060387772...
		

Programs

  • Mathematica
    RealDigits[ Fold[ Sqrt[ #1 + #2] &, 0, Reverse@ LucasL@ Range@ 45], 10, 111][[1]] (* Robert G. Wilson v, May 29 2009 *)

Extensions

More terms from Robert G. Wilson v, May 29 2009
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