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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A213570 Antidiagonal sums of the convolution array A213566.

Original entry on oeis.org

1, 9, 37, 110, 272, 598, 1213, 2323, 4265, 7588, 13184, 22500, 37881, 63125, 104381, 171602, 280896, 458330, 746085, 1212415, 1967761, 3190824, 5170752, 8375400, 13561777, 21954753, 35536213, 57512918, 93073520, 150613438
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..35], n-> Fibonacci(n+9)+Lucas(1,-1,n+8)[2] -(n^3+9*n^2 +39*n+81)); # G. C. Greubel, Jul 26 2019
  • Magma
    [Fibonacci(n+9) +Lucas(n+8) -(n^3+9*n^2+39*n+81): n in [1..35]]; // G. C. Greubel, Jul 26 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= Fibonacci[n]; c[n_]:= n^2;
    t[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_]:= Table[t[n, k], {k, 1, 60}]  (* A213566 *)
    d = Table[t[n, n], {n, 1, 40}] (* A213567 *)
    s[n_]:= Sum[t[i, n+1-i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A213570 *)
    (* Second program *)
    Table[Fibonacci[n+9] + LucasL[n+8] -(n^3+9*n^2+39*n+81), {n,35}] (* G. C. Greubel, Jul 26 2019 *)
  • PARI
    vector(35,n, f=fibonacci; 2*f(n+9)+f(n+7) -(n^3+9*n^2+39*n+81)) \\ G. C. Greubel, Jul 26 2019
    
  • Sage
    [fibonacci(n+9) +lucas_number2(n+8,1,-1) -(n^3+9*n^2+39*n+81) for n in (1..35)] # G. C. Greubel, Jul 26 2019
    

Formula

a(n) = 5*a(n-1) - 9*a(n-2) + 6*a(n-3) + a(n-4) - 3*a(n-5) + a(n-6).
G.f.: f(x)/g(x), where f(x) = x*(1 + 4*x + x^2) and g(x) = (1 - x - x^2)*(1 - x)^4.
a(n) = Fibonacci(n+9) + Lucas(n+8) - n*(n^2 + 9*n + 39) - 81. - Ehren Metcalfe, Jul 10 2019
a(n) = Sum_{k=1..n} k^3 * Fibonacci(n+1-k). - Greg Dresden, Feb 27 2022

A213572 Principal diagonal of the convolution array A213571.

Original entry on oeis.org

1, 13, 82, 406, 1809, 7659, 31588, 128476, 518611, 2084809, 8361918, 33497010, 134094757, 536608663, 2146926472, 8588754808, 34357247847, 137433710421, 549744803650, 2199000186670, 8796044787481, 35184271425283
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..30], n-> 2^(2*n+1) -2^n*(n+2) -Binomial(n+1, 2)); # G. C. Greubel, Jul 25 2019
  • Magma
    [2^(2*n+1) -2^n*(n+2) -Binomial(n+1, 2): n in [1..30]]; // G. C. Greubel, Jul 25 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= n; c[n_]:= -1 + 2^n;
    t[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_]:= Table[t[n, k], {k, 1, 60}]  (* A213571 *)
    d = Table[t[n, n], {n, 1, 40}] (* A213572 *)
    s[n_]:= Sum[t[i, n+1-i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A213581 *)
    (* Additional programs *)
    Table[2^(2*n+1) -2^n*(n+2)-Binomial[n+1, 2], {n,30}] (* G. C. Greubel, Jul 25 2019 *)
  • PARI
    vector(30, n, 2^(2*n+1) -2^n*(n+2) -binomial(n+1, 2)) \\ G. C. Greubel, Jul 25 2019
    
  • Sage
    [2^(2*n+1) -2^n*(n+2) -binomial(n+1, 2) for n in (1..30)] # G. C. Greubel, Jul 25 2019
    

Formula

a(n) = (2^(n+2)*(2^n-1) - (2^(n+1) + n + 1)*n)/2.
a(n) = 11*a(n-1) - 47*a(n-2) + 101*a(n-3) - 116*a(n-4) + 68*a(n-5) - 16*a(n-6).
G.f.: f(x)/g(x), where f(x) = x*(1 + 2*x - 14*x^2 + 14*x^3) and g(x) = (1 - 4*x)*((1 - x)^3)*(1 - 2*x)^2.

A213573 Rectangular array: (row n) = b**c, where b(h) = 2^(h-1), c(h) = (n-1+h)^2, n>=1, h>=1, and ** = convolution.

Original entry on oeis.org

1, 6, 4, 21, 17, 9, 58, 50, 34, 16, 141, 125, 93, 57, 25, 318, 286, 222, 150, 86, 36, 685, 621, 493, 349, 221, 121, 49, 1434, 1306, 1050, 762, 506, 306, 162, 64, 2949, 2693, 2181, 1605, 1093, 693, 405, 209, 81, 5998, 5486, 4462, 3310, 2286, 1486
Offset: 1

Views

Author

Clark Kimberling, Jun 18 2012

Keywords

Comments

Principal diagonal: A213574.
Antidiagonal sums: A213575.
row 1, (1,2,4,8,...)**(1,4,9,16...): A047520.
row 2, (1,2,4,8,...)**(4,9,16,25...).
row 3, (1,2,4,8,...)**(9,16,25,36...).
For a guide to related arrays, see A213500.

Examples

			Northwest corner (the array is read by falling antidiagonals):
   1,    6,   21,   58,  141,  318, ...
   4,   17,   50,  125,  286,  621, ...
   9,   34,   93,  222,  493, 1050, ...
  16,   57,  150,  349,  762, 1605, ...
  25,   86,  221,  506, 1093, 2286, ...
  36,  121,  306,  693, 1486, 3093, ...
  ...
		

Crossrefs

Cf. A213500.

Programs

  • GAP
    Flat(List([1..12], n-> List([1..n], k-> 2^(n-k+1)*((k+1)^2 +2)- ((n+2)^2 +2) ))); # G. C. Greubel, Jul 25 2019
  • Magma
    [2^(n-k+1)*((k+1)^2 +2)-((n+2)^2 +2): k in [1..n], n in [1..12]]; // G. C. Greubel, Jul 25 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= 2^(n-1); c[n_]:= n^2;
    T[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[T[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[T[n-k+1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_]:= Table[T[n, k], {k, 60}] (* A213573 *)
    d = Table[T[n, n], {n, 40}] (* A213574 *)
    s[n_]:= Sum[T[i, n+1-i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A213575 *)
    (* Additional programs *)
    Table[2^(n-k+1)*((k+1)^2 +2)-((n+2)^2 +2), {n,12}, {k, n}]//Flatten (* G. C. Greubel, Jul 25 2019 *)
  • PARI
    for(n=1,12, for(k=1,n, print1(2^(n-k+1)*((k+1)^2 +2)-((n+2)^2 +2), ", "))) \\ G. C. Greubel, Jul 25 2019
    
  • Sage
    [[2^(n-k+1)*((k+1)^2 +2)-((n+2)^2 +2) for k in (1..n)] for n in (1..12)] # G. C. Greubel, Jul 25 2019
    

Formula

T(n,k) = 5*T(n,k-1) - 9*T(n,k-2) + 7*T(n,k-3) - 2*T(n,k-4).
G.f. for row n: f(x)/g(x), where f(x) = n^2 - (2*n^2 - 2*n - 1)*x + (n - 1)*x^2 and g(x) = (1 - 2*x)*(1 - x)^3.
T(n,k) = 2^k*(n^2 + 2*n + 3) - (n + k + 2)^2 + 2*(n + k + 1) - 1. - G. C. Greubel, Jul 25 2019

A213574 Principal diagonal of the convolution array A213573.

Original entry on oeis.org

1, 17, 93, 349, 1093, 3093, 8221, 20957, 51861, 125509, 298477, 699789, 1621285, 3718325, 8453181, 19069885, 42728245, 95156901, 210762253, 464517485, 1019214021, 2227173397, 4848613213, 10519312029, 22749902293, 49056576773, 105495131181, 226291086157
Offset: 1

Views

Author

Clark Kimberling, Jun 18 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..30], n-> 2^n*(3+2*n+n^2) - (3+4*n+4*n^2)); # G. C. Greubel, Jul 25 2019
  • Magma
    [2^n*(3+2*n+n^2) - (3+4*n+4*n^2): n in [1..30]]; // G. C. Greubel, Jul 25 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= 2^(n-1); c[n_]:= n;
    t[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_]:= Table[t[n, k], {k, 1, 60}]  (* A213568 *)
    d = Table[t[n, n], {n, 1, 40}] (* A213569 *)
    s[n_]:= Sum[t[i, n+1-i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A047520 *)
    (* Additional programs *)
    LinearRecurrence[{9,-33,63,-66,36,-8},{1,17,93,349,1093,3093},30] (* Harvey P. Dale, Jun 25 2014 *)
    Rest[CoefficientList[Series[x(1+8x-27x^2+10x^3+16x^4)/(1-3x+2x^2)^3, {x, 0, 30}], x]] (* Vincenzo Librandi, Jun 26 2014 *)
  • PARI
    Vec(x*(1+8*x-27*x^2+10*x^3+16*x^4)/((1-x)^3*(1-2*x)^3) + O(x^30)) \\ Colin Barker, Oct 30 2017
    
  • PARI
    vector(30, n, 2^n*(3+2*n+n^2) - (3+4*n+4*n^2)) \\ G. C. Greubel, Jul 25 2019
    
  • Sage
    [2^n*(3+2*n+n^2) - (3+4*n+4*n^2) for n in (1..30)] # G. C. Greubel, Jul 25 2019
    

Formula

a(n) = 9*a(n-1) - 33*a(n-2) + 63*a(n-3) - 66*a(n-4) + 36*a(n-5) - 8*a(n-6).
G.f.: x*(1 + 8*x - 27*x^2 + 10*x^3 + 16*x^4)/(1 - 3*x + 2*x^2)^3.
a(n) = 2^n*(3+2*n+n^2) - (3+4*n+4*n^2). - Colin Barker, Oct 30 2017
E.g.f.: (3+6*x+4*x^2)*exp(2*x) - (3+8*x+4*x^2)*exp(x). - G. C. Greubel, Jul 25 2019

A213576 Rectangular array: (row n) = b**c, where b(h) = h, c(h) = F(n-1+h), where F=A000045 (Fibonacci numbers), n >= 1, h >= 1, and ** = convolution.

Original entry on oeis.org

1, 3, 1, 7, 4, 2, 14, 10, 7, 3, 26, 21, 17, 11, 5, 46, 40, 35, 27, 18, 8, 79, 72, 66, 56, 44, 29, 13, 133, 125, 118, 106, 91, 71, 47, 21, 221, 212, 204, 190, 172, 147, 115, 76, 34, 364, 354, 345, 329, 308, 278, 238, 186, 123, 55, 596, 585, 575, 557, 533, 498, 450, 385, 301, 199, 89
Offset: 1

Views

Author

Clark Kimberling, Jun 18 2012

Keywords

Comments

Principal diagonal: A213577.
Antidiagonal sums: A213578.
Row 1, (1,2,3,...)**(1,1,2,3,5,...): A001924;
Row 2, (1,2,3,...)**(1,2,3,5,8,...): A001891;
Row 3, (1,2,3,...)**(2,3,5,8,13,...): A033937;
Row 4, (1,2,3,...)**(3,5,8,13,21,...): A033960;
Row 5, (1,2,3,...)**(5,8,13,21,...): A037140;
Row 6, (1,2,3,...)**(8,13,21,34,...): A037157.
For a guide to related arrays, see A213500.
The falling antidiagonal rows can be computed by the sum Sum_{j=0..n-k} (n-k-j+1)*Fibonacci(k+j) which can also be seen as Fibonacci(n+4) - Lucas(k+2) - (n-k)*Fibonacci(k+1). - G. C. Greubel, Jul 05 2019

Examples

			Northwest corner (the array is read by falling antidiagonals):
  1,   3,   7,  14,  26,  46,  79
  1,   4,  10,  21,  40,  72, 125
  2,   7,  17,  35,  66, 118, 204
  3,  11,  27,  56, 106, 190, 329
  5,  18,  44,  91, 172, 308, 533
  8,  29,  71, 147, 278, 498, 862
		

Crossrefs

Cf. A213500.

Programs

  • GAP
    Flat(List([1..10], n-> List([1..n], k-> Fibonacci(n+4) - (n-k+1) *Fibonacci(k+1) - Fibonacci(k+3)))); # G. C. Greubel, Jul 05 2019
  • Magma
    [[Fibonacci(n+4) -(n-k)*Fibonacci(k+1) -Lucas(k+2): k in [1..n]]: n in [1..10]]; // G. C. Greubel, Jul 05 2019
    
  • Mathematica
    (* First Program *)
    b[n_]:= n; c[n_]:= Fibonacci[n];
    t[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]] (* A213576 *)
    r[n_]:= Table[t[n, k], {k,1,40}]  (* columns of antidiagonal triangle *)
    d = Table[t[n, n], {n, 1, 40}] (* A213577 *)
    s[n_]:= Sum[t[i, n + 1 - i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A213578 *)
    (* Second Program *)
    T[n_, k_]:= Fibonacci[n+4] - (n-k)*Fibonacci[k+1] - LucasL[k+2];
    Table[T[n,k], {n,10}, {k,n}]//Flatten (* G. C. Greubel, Jul 05 2019 *)
  • PARI
    T(n, k)= fibonacci(n+4) - (n-k+1)*fibonacci(k+1) - fibonacci(k+3);
    for(n=1,10, for(k=1,n, print1(T(n,k), ", "))) \\ G. C. Greubel, Jul 05 2019
    
  • Sage
    [[fibonacci(n+4) - (n-k+1)*fibonacci(k+1) - fibonacci(k+3) for k in (1..n)] for n in (1..10)] # G. C. Greubel, Jul 05 2019
    

Formula

Rows: T(n,k) = 3*T(n,k-1) - 2*T(n,k-2) - T(n,k-3) + T(n,k-4).
Columns: T(n,k) = T(n-1,k) + T(n-2,k).
G.f. for row n: f(x)/g(x), where f(x) = F(n) - F(n-1)*x and g(x) = (1 - x - x^2)*(1 - x)^2.
T(n,k) = F(n+k+3) - k*F(n+1) - F(n+3). - Ehren Metcalfe, Jul 04 2019

A213577 Principal diagonal of the convolution array A213576.

Original entry on oeis.org

1, 4, 17, 56, 172, 498, 1395, 3820, 10307, 27534, 73064, 193012, 508341, 1336132, 3507189, 9197732, 24107124, 63159782, 165433895, 433246860, 1134484871, 2970509594, 7777554192, 20363014056, 53312938537, 139578241348
Offset: 1

Views

Author

Clark Kimberling, Jun 18 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..40], n-> Fibonacci(2*n+3) - Fibonacci(n+3) - n*Fibonacci(n+1)); # G. C. Greubel, Jul 05 2019
  • Magma
    [Fibonacci(2*n+3) -Fibonacci(n+3) -n*Fibonacci(n+1): n in [1..40]]; // G. C. Greubel, Jul 05 2019
    
  • Mathematica
    (See A213576.)
    LinearRecurrence[{5,-6,-3,6,1,-1},{1,4,17,56,172,498},30] (* Harvey P. Dale, Aug 23 2012 *)
    Table[Fibonacci[2n+3] -Fibonacci[n+3] -n*Fibonacci[n+1], {n,1,40}] (* G. C. Greubel, Jul 05 2019 *)
  • PARI
    vector(40, n, fibonacci(2*n+3) - fibonacci(n+3) - n*fibonacci(n+1)) \\ G. C. Greubel, Jul 05 2019
    
  • Sage
    [fibonacci(2*n+3) - fibonacci(n+3) - n*fibonacci(n+1) for n in (1..40)] # G. C. Greubel, Jul 05 2019
    

Formula

a(n) = 5*a(n-1) - 6*a(n-2) - 3*a(n-3) + 6*a(n-4) + a(n-5) - a(n-6).
G.f.: x*(1 - x + 3*x^2 - 2*x^3)/((1 - 3*x + x^2)*(1 - x - x^2)^2).
a(n) = Fibonacci(2*n+3) - Fibonacci(n+3) - n*Fibonacci(n+1). - G. C. Greubel, Jul 05 2019

A213581 Antidiagonal sums of the convolution array A213571.

Original entry on oeis.org

1, 8, 36, 124, 367, 988, 2498, 6048, 14197, 32576, 73472, 163508, 360027, 785908, 1703294, 3669240, 7863393, 16776120, 35650300, 75495980, 159381831, 335542348, 704640826, 1476392464, 3087004877, 6442447728, 13421769208
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..35], n-> 2^(n+2)*(n-2) - (n^3+3*n^2-10*n-48)/6); # G. C. Greubel, Jul 26 2019
  • Magma
    [2^(n+2)*(n-2) - (n^3+3*n^2-10*n-48)/6: n in [1..35]]; // G. C. Greubel, Jul 26 2019
    
  • Mathematica
    (* First Program *)
    b[n_]:= n; c[n_]:= -1 + 2^n;
    t[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_]:= Table[t[n, k], {k, 1, 60}]  (* A213571 *)
    d = Table[t[n, n], {n, 1, 40}] (* A213572 *)
    s[n_]:= Sum[t[i, n+1-i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A213581 *)
    (* Second program *)
    Table[2^(n+2)*(n-2) - (n^3+3*n^2-10*n-48)/6, {n,35}] (* G. C. Greubel, Jul 26 2019 *)
  • PARI
    vector(35, n, 2^(n+2)*(n-2) - (n^3+3*n^2-10*n-48)/6) \\ G. C. Greubel, Jul 26 2019
    
  • Sage
    [2^(n+2)*(n-2) - (n^3+3*n^2-10*n-48)/6 for n in (1..35)] # G. C. Greubel, Jul 26 2019
    

Formula

a(n) = 8*a(n-1) - 26*a(n-2) + 44*a(n-3) - 41*a(n-4) + 20*a(n-5) - 4*a(n-6).
G.f.: f(x)/g(x), where f(x) = x*(1 - 2*x^2) and g(x) = (1 - x)^4*(1 - 2*x)^2.
a(n) = 8 +(n-2)*2^(n+2) -(n-2)*n*(n+5)/6. - Bruno Berselli, Jul 09 2012

A213582 Rectangular array: (row n) = b**c, where b(h) = -1 + 2^h, c(h) = n-1+h, n>=1, h>=1, and ** = convolution.

Original entry on oeis.org

1, 5, 2, 16, 9, 3, 42, 27, 13, 4, 99, 68, 38, 17, 5, 219, 156, 94, 49, 21, 6, 466, 339, 213, 120, 60, 25, 7, 968, 713, 459, 270, 146, 71, 29, 8, 1981, 1470, 960, 579, 327, 172, 82, 33, 9, 4017, 2994, 1972, 1207, 699, 384, 198, 93, 37, 10, 8100, 6053, 4007, 2474, 1454, 819, 441, 224, 104, 41, 11
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Comments

Principal diagonal: A213583.
Antidiagonal sums: A156928.
Row 1, (1,3,7,15,31,...)**(1,2,3,4,5,...): A002662.
Row 2, (1,3,7,15,31,...)**(2,3,4,5,6,...)
Row 3, (1,3,7,15,31,...)**(3,4,5,6,7,...)
For a guide to related arrays, see A213500.

Examples

			Northwest corner (the array is read by falling antidiagonals):
1...5....16...42....99....219
2...9....27...68....156...339
3...13...38...94....213...459
4...17...49...120...270...579
5...21...60...146...327...699
6...25...71...172...384...819
		

Crossrefs

Programs

  • GAP
    Flat(List([1..12], n-> List([1..n], k-> 2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2 ))); # G. C. Greubel, Jul 08 2019
  • Magma
    [[2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2: k in [1..n]]: n in [1..12]]; // G. C. Greubel, Jul 08 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= 2^n - 1; c[n_]:= n;
    T[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[T[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[T[n-k+1, k], {n, 12}, {k, n, 1, -1}]] (* A213582 *)
    r[n_]:= Table[T[n, k], {k, 40}]
    Table[T[n, n], {n, 1, 40}] (* A213583 *)
    s[n_]:= Sum[T[i, n+1-i], {i, 1, n}]
    Table[s[n], {n, 1, 50}] (* A156928 *)
    (* Second program *)
    Table[2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2, {n, 12}, {k, n}]//Flatten (* G. C. Greubel, Jul 08 2019 *)
  • PARI
    t(n,k) = 2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2;
    for(n=1,12, for(k=1,n, print1(t(n,k), ", "))) \\ G. C. Greubel, Jul 08 2019
    
  • Sage
    [[2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2 for k in (1..n)] for n in (1..12)] # G. C. Greubel, Jul 08 2019
    

Formula

T(n,k) = 5*T(n,k-1) - 9*T(n,k-2) + 7*T(n,k-3) - 2*T(n,k-4).
G.f. for row n: f(x)/g(x), where f(x) = n - (n-1)*x and g(x) = (1-2*x) *(1-x)^3.
T(n,k) = 2*(n+1)*(2^k - 1) - k*(k + 2*n + 3)/2. - G. C. Greubel, Jul 08 2019

A213588 Principal diagonal of the convolution array A213587.

Original entry on oeis.org

1, 7, 27, 96, 315, 994, 3043, 9123, 26909, 78370, 225911, 645732, 1832677, 5170111, 14509695, 40537284, 112805043, 312808198, 864707719, 2383649115, 6554153921, 17980221382, 49222822127, 134495771976, 366850762825
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..30], n-> (n*Lucas(1,-1,2*n+2)[2] - Fibonacci(n)*Lucas(1,-1,n-1)[2])/5); # G. C. Greubel, Jul 08 2019
  • Magma
    [(n*Lucas(2*n+2) - Fibonacci(n)*Lucas(n-1))/5: n in [1..30]]; // G. C. Greubel, Jul 08 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= Fibonacci[n+1]; c[n_]:= Fibonacci[n+1];
    T[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[T[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[T[n-k+1, k], {n, 12}, {k, n, 1, -1}]] (* A213587 *)
    r[n_]:= Table[T[n, k], {k, 40}]  (* columns of antidiagonal triangle *)
    Table[T[n, n], {n, 1, 40}] (* A213588 *)
    s[n_]:= Sum[T[i, n+1-i], {i, 1, n}]
    Table[s[n], {n, 1, 50}] (* A213589 *)
    (* Second program *)
    Table[(n*LucasL[2n+2] -Fibonacci[n]*LucasL[n-1])/5, {n, 30}] (* G. C. Greubel, Jul 08 2019 *)
  • PARI
    lucas(n) = fibonacci(n+1) + fibonacci(n-1);
    vector(30, n, (n*lucas(2*n+2) - fibonacci(n)*lucas(n-1))/5) \\ G. C. Greubel, Jul 08 2019
    
  • Sage
    [(n*lucas_number2(2*n+2,1,-1) - fibonacci(n)*lucas_number2(n-1, 1, -1))/5 for n in (1..30)] # G. C. Greubel, Jul 08 2019
    

Formula

a(n) = 5*a(n-1) - 5*a(n-2) - 5*a(n-3) + 5*a(n-4) - a(n-5).
G.f.: x*(1 + 2*x - 3*x^2 + x^3)/((1 + x)*(1 - 3*x + x^2)^2).
a(n) = (n*Lucas(2*n+2) - Fibonacci(n)*Lucas(n-1))/5. - G. C. Greubel, Jul 08 2019

A213589 Antidiagonal sums of the convolution array A213587.

Original entry on oeis.org

1, 6, 20, 55, 135, 308, 668, 1395, 2830, 5610, 10914, 20904, 39515, 73860, 136720, 250937, 457137, 827260, 1488190, 2662905, 4741946, 8407236, 14846100, 26120400, 45801925, 80064018, 139553708, 242597035, 420678315, 727792580
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Crossrefs

Programs

  • GAP
    F:=Fibonacci;; List([1..35], n-> (n+1)*((n+2)*F(n+3) + 2*(n-2)*F(n+2))/10) # G. C. Greubel, Jul 08 2019
  • Magma
    F:=Fibonacci; [(n+1)*((n+2)*F(n+3) + 2*(n-2)*F(n+2))/10: n in [1..35]]; // G. C. Greubel, Jul 08 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= Fibonacci[n+1]; c[n_]:= Fibonacci[n+1];
    T[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[T[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[T[n-k+1, k], {n, 12}, {k, n, 1, -1}]] (* A213587 *)
    r[n_]:= Table[T[n, k], {k, 40}]  (* columns of antidiagonal triangle *)
    Table[T[n, n], {n, 1, 40}] (* A213588 *)
    s[n_]:= Sum[T[i, n+1-i], {i, 1, n}]
    Table[s[n], {n, 1, 50}] (* A213589 *)
    (* Second program *)
    Table[(n+1)*(n*LucasL[n+3] -2*Fibonacci[n])/10, {n, 35}] (* G. C. Greubel, Jul 08 2019 *)
  • Maxima
    a(n):=(n+1)/2*sum((n-j)*binomial(n-j+1,j),j,0,(n+1)/2); /* Vladimir Kruchinin, Apr 09 2016 */
    
  • PARI
    vector(35, n, f=fibonacci; (n+1)*((n+2)*f(n+3)+ 2*(n-2)*f(n+2) )/10) \\ G. C. Greubel, Jul 08 2019
    
  • Sage
    f=fibonacci; [(n+1)*((n+2)*f(n+3)+ 2*(n-2)*f(n+2) )/10 for n in (1..35)] # G. C. Greubel, Jul 08 2019
    

Formula

a(n) = 3*a(n-1) - 5*a(n-3) + 3*a(n-5) + a(n-6).
G.f.: x*(1 + 3*x + 2*x^2)/(1 - x - x^2)^3.
a(n) = (n+1)/2*Sum_{j=0..(n+1)/2}((n-j)*binomial(n-j+1,j)). - Vladimir Kruchinin, Apr 09 2016
a(n) = (n+1)*(n*Lucas(n+3) - 2*Fibonacci(n))/10 = (n+1)*((n+2) *Fibonacci(n+3) + 2*(n-2)*Fibonacci(n+2))/10. - G. C. Greubel, Jul 08 2019
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