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.

Previous Showing 11-16 of 16 results.

A210730 a(n) = a(n-1) + a(n-2) + n + 2 with n>1, a(0)=a(1)=0.

Original entry on oeis.org

0, 0, 4, 9, 19, 35, 62, 106, 178, 295, 485, 793, 1292, 2100, 3408, 5525, 8951, 14495, 23466, 37982, 61470, 99475, 160969, 260469, 421464, 681960, 1103452, 1785441, 2888923, 4674395, 7563350, 12237778, 19801162, 32038975, 51840173, 83879185, 135719396
Offset: 0

Views

Author

Alex Ratushnyak, May 10 2012

Keywords

Comments

Deleting the 0's leaves row 4 of the convolution array A213579. - Clark Kimberling, Jun 20 2012

Crossrefs

Cf. A033818: a(n)=a(n-1)+a(n-2)+n-5, a(0)=a(1)=0 (except first 2 terms and sign).
Cf. A002062: a(n)=a(n-1)+a(n-2)+n-4, a(0)=a(1)=0 (except the first term and sign).
Cf. A065220: a(n)=a(n-1)+a(n-2)+n-3, a(0)=a(1)=0.
Cf. A001924: a(n)=a(n-1)+a(n-2)+n-1, a(0)=a(1)=0 (except the first term).
Cf. A023548: a(n)=a(n-1)+a(n-2)+n, a(0)=a(1)=0 (except first 2 terms).
Cf. A023552: a(n)=a(n-1)+a(n-2)+n+1, a(0)=a(1)=0 (except first 2 terms).
Cf. A210731: a(n)=a(n-1)+a(n-2)+n+3, a(0)=a(1)=0.

Programs

  • GAP
    F:=Fibonacci;; List([0..40], n-> F(n+3)+3*F(n+1)-n-5); # G. C. Greubel, Jul 08 2019
  • Magma
    I:=[0, 0, 4, 9]; [n le 4 select I[n] else 3*Self(n-1)-2*Self(n-2)-Self(n-3)+Self(n-4): n in [1..37]]; // Bruno Berselli, May 10 2012
    
  • Magma
    F:=Fibonacci; [F(n+3)+3*F(n+1)-n-5: n in [0..40]]; // G. C. Greubel, Jul 08 2019
    
  • Mathematica
    RecurrenceTable[{a[0]==a[1]==0, a[n]==a[n-1] +a[n-2] +n+2}, a, {n, 40}] (* Bruno Berselli, May 10 2012 *)
    LinearRecurrence[{3,-2,-1,1},{0,0,4,9},40] (* Harvey P. Dale, Jul 24 2013 *)
    With[{F=Fibonacci}, Table[F[n+3]+2*F[n+1]-n-5, {n, 40}]] (* G. C. Greubel, Jul 08 2019 *)
  • PARI
    concat(vector(2), Vec(x^2*(4-3*x)/((1-x)^2*(1-x-x^2)) + O(x^50))) \\ Colin Barker, Mar 11 2017
    
  • PARI
    vector(40, n, n--; f=fibonacci; f(n+3)+3*f(n+1)-n-5) \\ G. C. Greubel, Jul 08 2019
    
  • Sage
    f=fibonacci; [f(n+3)+3*f(n+1)-n-5 for n in (0..40)] # G. C. Greubel, Jul 08 2019
    

Formula

G.f.: x^2*(4-3*x)/((1-x)^2*(1-x-x^2)). - Bruno Berselli, May 10 2012
a(n) = A210677(n)-1. - Bruno Berselli, May 10 2012
a(0)=0, a(1)=0, a(2)=4, a(3)=9, a(n) = 3*a(n-1)-2*a(n-2)-a(n-3)+a(n-4). - Harvey P. Dale, Jul 24 2013
a(n) = -5 + (2^(-1-n)*((1-sqrt(5))^n*(-7+5*sqrt(5)) + (1+sqrt(5))^n*(7+5*sqrt(5)))) / sqrt(5) - n. - Colin Barker, Mar 11 2017
a(n) = Fibonacci(n+3) + 3*Fibonacci(n+1) - n - 5. - G. C. Greubel, Jul 08 2019

A210731 a(n) = a(n-1) + a(n-2) + n + 3 with n>1, a(0) = a(1) = 0.

Original entry on oeis.org

0, 0, 5, 11, 23, 42, 74, 126, 211, 349, 573, 936, 1524, 2476, 4017, 6511, 10547, 17078, 27646, 44746, 72415, 117185, 189625, 306836, 496488, 803352, 1299869, 2103251, 3403151, 5506434, 8909618, 14416086, 23325739, 37741861, 61067637, 98809536
Offset: 0

Views

Author

Alex Ratushnyak, May 10 2012

Keywords

Crossrefs

Cf. A033818: a(n)=a(n-1)+a(n-2)+n-5, a(0)=a(1)=0 (except first 2 terms and sign).
Cf. A002062: a(n)=a(n-1)+a(n-2)+n-4, a(0)=a(1)=0 (except the first term and sign).
Cf. A065220: a(n)=a(n-1)+a(n-2)+n-3, a(0)=a(1)=0.
Cf. A001924: a(n)=a(n-1)+a(n-2)+n-1, a(0)=a(1)=0 (except the first term).
Cf. A023548: a(n)=a(n-1)+a(n-2)+n, a(0)=a(1)=0 (except first 2 terms).
Cf. A023552: a(n)=a(n-1)+a(n-2)+n+1, a(0)=a(1)=0 (except first 2 terms).
Cf. A210730: a(n)=a(n-1)+a(n-2)+n+2, a(0)=a(1)=0.

Programs

  • GAP
    F:=Fibonacci;; List([0..40], n-> F(n+3)+4*F(n+1)-n-6); # G. C. Greubel, Jul 09 2019
  • Magma
    F:=Fibonacci; [F(n+3)+4*F(n+1)-n-6: n in [0..40]]; // G. C. Greubel, Jul 09 2019
    
  • Mathematica
    With[{F = Fibonacci}, Table[F[n+3]+4*F[n+1]-n-6, {n,0,40}]] (* G. C. Greubel, Jul 09 2019 *)
    nxt[{n_,a_,b_}]:={n+1,b,a+b+n+4}; NestList[nxt,{1,0,0},40][[;;,2]] (* or *) LinearRecurrence[{3,-2,-1,1},{0,0,5,11},40] (* Harvey P. Dale, Dec 30 2024 *)
  • PARI
    vector(40, n, n--; f=fibonacci; f(n+3)+4*f(n+1)-n-6) \\ G. C. Greubel, Jul 09 2019
    
  • Sage
    f=fibonacci; [f(n+3)+4*f(n+1)-n-6 for n in (0..40)] # G. C. Greubel, Jul 09 2019
    

Formula

From Colin Barker, Jun 29 2012: (Start)
a(n) = 3*a(n-1) - 2*a(n-2) - a(n-3) + a(n-4).
G.f.: x^2*(5-4*x)/((1-x)^2*(1-x-x^2)). (End)
a(n) = Fibonacci(n+3) + 4*Fibonacci(n+1) - (n+6). - G. C. Greubel, Jul 09 2019

A033814 Convolution of positive integers n with Lucas numbers L(k)(A000032) for k >= 4.

Original entry on oeis.org

7, 25, 61, 126, 238, 426, 737, 1247, 2079, 3432, 5628, 9188, 14955, 24293, 39409, 63874, 103466, 167534, 271205, 438955, 710387, 1149580, 1860216, 3010056, 4870543, 7880881, 12751717, 20632902, 33384934, 54018162, 87403433, 141421943, 228825735, 370248048
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • GAP
    List([1..40], n-> Lucas(1, -1, n+7)[2] -11*n-29 ) # G. C. Greubel, Jun 01 2019
    
  • Magma
    [Lucas(n+7) - 11*n - 29 : n in [1..40]]; // G. C. Greubel, Jun 01 2019
    
  • Mathematica
    Table[LucasL[n+7] -11*n-29, {n,1,40}] (* G. C. Greubel, Jun 01 2019 *)
  • PARI
    vector(40, n, fibonacci(n+8) + fibonacci(n+6) -11*n-29) \\ G. C. Greubel, Jun 01 2019
    
  • Python
    from sympy import lucas
    def a(n): return lucas(n+7) - 11*n - 29
    print([a(n) for n in range(1, 35)]) # Michael S. Branicky, Jul 25 2021
  • Sage
    [lucas_number2(n+7,1,-1) -11*n-29 for n in (1..40)] # G. C. Greubel, Jun 01 2019
    

Formula

a(n) = L(7)*(F(n+1)-1) + L(6)*F(n) - L(5)*n, F(n): Fibonacci (A000045) and L(n): Lucas (A000032).
G.f.: x*(7+4*x)/((1-x-x^2)*(1-x)^2).
a(n) = A000032(n+7) - 11*n - 29. - G. C. Greubel, Jun 01 2019

A033817 Convolution of natural numbers n >= 1 with Lucas numbers L(k) for k >= -4.

Original entry on oeis.org

7, 10, 16, 21, 28, 36, 47, 62, 84, 117, 168, 248, 375, 578, 904, 1429, 2276, 3644, 5855, 9430, 15212, 24565, 39696, 64176, 103783, 167866, 271552, 439317, 710764, 1149972, 1860623, 3010478, 4870980, 7881333, 12752184, 20633384, 33385431, 54018674, 87403960, 141422485
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • GAP
    List([1..40], n-> Lucas(1, -1, n-1)[2] +4*n+1 ) # G. C. Greubel, Jun 01 2019
  • Magma
    [Lucas(n-1) + 4*n + 1 : n in [1..40]]; // G. C. Greubel, Jun 01 2019
    
  • Mathematica
    Table[LucasL[n-1] +4*n+1, {n,1,40}] (* G. C. Greubel, Jun 01 2019 *)
  • PARI
    vector(40, n, fibonacci(n) + fibonacci(n-2) +4*n+1) \\ G. C. Greubel, Jun 01 2019
    
  • Sage
    [lucas_number2(n-1,1,-1) +4*n+1 for n in (1..40)] # G. C. Greubel, Jun 01 2019
    

Formula

a(n) = L(-1)*(F(n+1)-1) + L(-2)*F(n) - L(-3)*n, F(n): Fibonacci (A000045), L(n): Lucas (A000032) with L(-n)=(-1)^n*L(n)
G.f.: x*(7-11*x)/((1-x-x^2)*(1-x)^2).
a(n) = Lucas(n-1) + 4*n + 1. - G. C. Greubel, Jun 01 2019

Extensions

Terms a(31) onward added by G. C. Greubel, Jun 01 2019

A163704 Number of n X 2 binary arrays with all 1s connected, a path of 1s from left column to lower right corner, and no 1 having more than two 1s adjacent.

Original entry on oeis.org

1, 5, 11, 21, 38, 66, 112, 187, 309, 507, 828, 1348, 2190, 3553, 5759, 9329, 15106, 24454, 39580, 64055, 103657, 167735, 271416, 439176, 710618, 1149821, 1860467, 3010317, 4870814, 7881162, 12752008, 20633203, 33385245, 54018483, 87403764
Offset: 1

Views

Author

R. H. Hardin, Aug 03 2009

Keywords

Examples

			All solutions for n=3:
  0 0   0 0   0 0   0 0   1 0   0 1   1 1   0 0   1 0   1 1   1 1
  0 0   0 1   1 0   1 1   1 0   0 1   1 0   1 1   1 1   0 1   0 1
  1 1   1 1   1 1   1 1   1 1   1 1   1 1   0 1   0 1   0 1   1 1
		

Crossrefs

Cf. A023548. - R. J. Mathar, Aug 06 2009

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - a(n-3) + a(n-4) for n >= 6.
Conjectures from Colin Barker, Mar 25 2018: (Start)
G.f.: x*(1 + 2*x - 2*x^2 - x^3 + x^4) / ((1 - x)^2*(1 - x - x^2)).
a(n) = -4 + (2^(-n)*((1-sqrt(5))^n*(-5+2*sqrt(5)) + (1+sqrt(5))^n*(5+2*sqrt(5)))) / sqrt(5) - n for n>1.
(End)

A033813 Convolution of natural numbers n >= 1 with Lucas numbers L(k) (A000032) for k >= 3.

Original entry on oeis.org

4, 15, 37, 77, 146, 262, 454, 769, 1283, 2119, 3476, 5676, 9240, 15011, 24353, 39473, 63942, 103538, 167610, 271285, 439039, 710475, 1149672, 1860312, 3010156, 4870647, 7880989, 12751829, 20633018, 33385054, 54018286, 87403561, 141422075, 228825871, 370248188
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{3,-2,-1,1},{4,15,37,77},40] (* or *) Rest[ CoefficientList[ Series[x (4+3x)/((1-x-x^2)(1-x)^2),{x,0,40}],x]] (* Harvey P. Dale, May 23 2011 *)

Formula

a(n) = L(6)*(F(n+1)-1)+L(5)*F(n)-L(4)*n, F(n): Fibonacci (A000045).
G.f.: x*(4+3*x)/((1-x-x^2)*(1-x)^2).
a(0)=4, a(1)=15, a(2)=37, a(3)=77, a(n) = 3*a(n-1)-2*a(n-2)-a(n-3)+a(n-4). - Harvey P. Dale, May 23 2011

Extensions

More terms from Jason Yuen, Aug 27 2025
Previous Showing 11-16 of 16 results.