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 1-3 of 3 results.

A316349 Consider coefficients U(m,L,k) defined by the identity Sum_{k=1..L} Sum_{j=0..m} A302971(m,j)/A304042(m,j) * k^j * (T-k)^j = Sum_{k=0..m} (-1)^(m-k) * U(m,L,k) * T^k that holds for all positive integers L,m,T. This sequence gives 3-column table read by rows, where the n-th row lists coefficients U(2,n,k) for k = 0, 1, 2; n >= 1.

Original entry on oeis.org

31, 60, 30, 512, 540, 150, 2943, 2160, 420, 10624, 6000, 900, 29375, 13500, 1650, 68256, 26460, 2730, 140287, 47040, 4200, 263168, 77760, 6120, 459999, 121500, 8550, 760000, 181500, 11550, 1199231, 261360, 15180, 1821312, 365040, 19500, 2678143, 496860, 24570, 3830624, 661500, 30450
Offset: 1

Views

Author

Kolosov Petro, Jun 29 2018

Keywords

Comments

For L=T, the identity takes form T^(2m+1) = Sum_{k=0..m} (-1)^(m-k)*U(m,T,k)*T^k, which holds for all positive integers T and m.

Examples

			       column   column  column
   L     k=0      k=1     k=2
  --  -------  -------  ------
   1       31       60      30
   2      512      540     150
   3     2943     2160     420
   4    10624     6000     900
   5    29375    13500    1650
   6    68256    26460    2730
   7   140287    47040    4200
   8   263168    77760    6120
   9   459999   121500    8550
  10   760000   181500   11550
  11  1199231   261360   15180
  12  1821312   365040   19500
  ...
		

Crossrefs

The case m=1 is A320047.
The case m=3 is A316387.
Column k=0 is A316457.
Column k=1 is A316458.
Column k=2 is A316459.

Programs

  • Mathematica
    (* Define the R[n,k] := A302971(m,j)/A304042(m,j) *)
    R[n_, k_] := 0
    R[n_, k_] := (2 k + 1)*Binomial[2 k, k]*
       Sum[R[n, j]*Binomial[j, 2 k + 1]*(-1)^(j - 1)/(j - k)*
       BernoulliB[2 j - 2 k], {j, 2 k + 1, n}] /; 2 k + 1 <= n
    R[n_, k_] := (2 n + 1)*Binomial[2 n, n] /; k == n;
    (* Define the U(m,l,t) coefficients *)
    U[m_, l_, t_] := (-1)^m Sum[Sum[Binomial[j, t] R[m,j] k^(2 j - t) (-1)^j, {j, t, m}], {k, 1, l}];
    (* Define the value of the variable 'm', should be m = 2 for A316349 *)
    m = 2;
    (* Print first 10 rows of U(m,l,t) coefficients over l: 1 <= l <= 10 *)
    Column[Table[U[m, l, t], {l, 1, 10}, {t, 0, m}]]

Formula

U(2,n,0) = 6*n^5 + 15*n^4 + 10*n^3; U(2,n,1) = 15*n^4 + 30*n^3 + 15*n^2; U(2,n,2) = 10*n^3 + 15*n^2 + 5*n. - Max Alekseyev, Sep 06 2018
From Colin Barker, Jul 06 2018: (Start)
G.f.: x*(31 + 60*x + 30*x^2 + 326*x^3 + 180*x^4 - 30*x^5 + 336*x^6 - 180*x^7 - 30*x^8 + 26*x^9 - 60*x^10 + 30*x^11 + x^12) / ((1 - x)^6*(1 + x + x^2)^6).
a(n) = 6*a(n-3) - 15*a(n-6) + 20*a(n-9) - 15*a(n-12) + 6*a(n-15) - a(n-18) for n>18. (End)
U(m,L,t) = (-1)^m * Sum_{k=1..L} Sum_{j=t..m} binomial(j,t) * R(m,j) * k^{2j-t} * (-1)^j, where m = 1, L >= 1 and R(m,j) = A302971(m,j)/A304042(m,j); after Max Alekseyev, see links.

Extensions

Edited by Max Alekseyev, Sep 06 2018

A316457 Expansion of x*(31 + 326*x + 336*x^2 + 26*x^3 + x^4) / (1 - x)^6.

Original entry on oeis.org

31, 512, 2943, 10624, 29375, 68256, 140287, 263168, 459999, 760000, 1199231, 1821312, 2678143, 3830624, 5349375, 7315456, 9821087, 12970368, 16879999, 21680000, 27514431, 34542112, 42937343, 52890624, 64609375, 78318656, 94261887, 112701568, 133919999
Offset: 1

Views

Author

Colin Barker, Aug 12 2018

Keywords

Comments

Seems to be the first column of A316349.

Crossrefs

Programs

  • PARI
    Vec(x*(31 + 326*x + 336*x^2 + 26*x^3 + x^4) / (1 - x)^6 + O(x^40))
    
  • PARI
    a(n) = 6*n^5 + 15*n^4 + 10*n^3

Formula

G.f.: x*(31 + 326*x + 336*x^2 + 26*x^3 + x^4) / (1 - x)^6.
a(n) = 6*n^5 + 15*n^4 + 10*n^3.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.

A316459 Expansion of 30*x*(1 + x) / (1 - x)^4.

Original entry on oeis.org

30, 150, 420, 900, 1650, 2730, 4200, 6120, 8550, 11550, 15180, 19500, 24570, 30450, 37200, 44880, 53550, 63270, 74100, 86100, 99330, 113850, 129720, 147000, 165750, 186030, 207900, 231420, 256650, 283650, 312480, 343200, 375870, 410550, 447300, 486180
Offset: 1

Views

Author

Colin Barker, Aug 12 2018

Keywords

Comments

Seems to be the third column of A316349.

Crossrefs

Programs

  • PARI
    Vec(30*x*(1 + x) / (1 - x)^4 + O(x^40))
    
  • PARI
    a(n) = 10*n^3 + 15*n^2 + 5*n

Formula

G.f.: 30*x*(1 + x) / (1 - x)^4.
a(n) = 30 * A000330(n).
a(n) = 10*n^3 + 15*n^2 + 5*n.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>4.
Showing 1-3 of 3 results.