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 1-6 of 6 results.

A304338 Row sums of A304336.

Original entry on oeis.org

1, 1, 4, 26, 239, 2902, 44441, 830636, 18495910, 481474188, 14432543299, 492063896964, 18885525411110, 808850019798316, 38368738864146619, 2002743853356179552, 114374154959904537521, 7110312727864509410026, 479017371580348640009295
Offset: 0

Views

Author

Peter Luschny, May 11 2018

Keywords

Crossrefs

Programs

  • Maple
    A304338 := n -> add(add((-1)^j*binomial(2*k,j)*(k-j)^(2*n), j=0..k)/(k!)^2, k=0..n): seq(A304338(n), n=0..18);
  • PARI
    a(n) = sum(k=0, n, sum(j=0, k, (-1)^j*binomial(2*k,j)*(k-j)^(2*n)) / (k!)^2); \\ Michel Marcus, May 11 2018

Formula

a(n) = Sum_{k=0..n} Sum_{j=0..k} (-1)^j*binomial(2*k,j)*(k-j)^(2*n) / (k!)^2.

A304330 T(n, k) = Sum_{j=0..k} (-1)^j*binomial(2*k, j)*(k - j)^(2*n), triangle read by rows, n >= 0 and 0 <= k <= n.

Original entry on oeis.org

1, 0, 1, 0, 1, 12, 0, 1, 60, 360, 0, 1, 252, 5040, 20160, 0, 1, 1020, 52920, 604800, 1814400, 0, 1, 4092, 506880, 12640320, 99792000, 239500800, 0, 1, 16380, 4684680, 230630400, 3632428800, 21794572800, 43589145600, 0, 1, 65532, 42653520, 3952428480, 111567456000, 1264085222400, 6102480384000, 10461394944000
Offset: 0

Views

Author

Peter Luschny, May 11 2018

Keywords

Examples

			Triangle starts:
  [0] 1;
  [1] 0, 1;
  [2] 0, 1,    12;
  [3] 0, 1,    60,     360;
  [4] 0, 1,   252,    5040,     20160;
  [5] 0, 1,  1020,   52920,    604800,    1814400;
  [6] 0, 1,  4092,  506880,  12640320,   99792000,   239500800;
  [7] 0, 1, 16380, 4684680, 230630400, 3632428800, 21794572800, 43589145600;
		

Crossrefs

Row sums are A100872, T(n,2) = A058896, T(n,n) = A002674, T(n,n-1)= A091032.

Programs

  • Maple
    T := (n, k) -> add((-1)^j*binomial(2*k,j)*(k-j)^(2*n), j=0..k):
    for n from 0 to 8 do seq(T(n, k), k=0..n) od;
  • PARI
    T(n, k) = sum(j=0, k, (-1)^j*binomial(2*k, j)*(k - j)^(2*n)); \\ Michel Marcus, Aug 03 2025

A304334 T(n, k) = Sum_{j=0..k} (-1)^j*binomial(2*k, j)*(k - j)^(2*n)/k!, triangle read by rows, n >= 0 and 0 <= k <= n.

Original entry on oeis.org

1, 0, 1, 0, 1, 6, 0, 1, 30, 60, 0, 1, 126, 840, 840, 0, 1, 510, 8820, 25200, 15120, 0, 1, 2046, 84480, 526680, 831600, 332640, 0, 1, 8190, 780780, 9609600, 30270240, 30270240, 8648640, 0, 1, 32766, 7108920, 164684520, 929728800, 1755673920, 1210809600, 259459200
Offset: 0

Views

Author

Peter Luschny, May 11 2018

Keywords

Examples

			Triangle starts:
[0] 1
[1] 0, 1
[2] 0, 1,     6
[3] 0, 1,    30,      60
[4] 0, 1,   126,     840,       840
[5] 0, 1,   510,    8820,     25200,     15120
[6] 0, 1,  2046,   84480,    526680,    831600,     332640
[7] 0, 1,  8190,  780780,   9609600,  30270240,   30270240,    8648640
[8] 0, 1, 32766, 7108920, 164684520, 929728800, 1755673920, 1210809600, 259459200
		

Crossrefs

Row sums are bisection of A081562, T(n,n) ~ A000407, T(n,n-1) ~ A048854(n,2), T(n,2) ~ A002446.

Programs

  • Maple
    A304334 := (n, k) -> add((-1)^j*binomial(2*k,j)*(k-j)^(2*n), j=0..k)/k!:
    for n from 0 to 8 do seq(A304334(n, k), k=0..n) od;
  • PARI
    T(n, k) = sum(j=0, k, (-1)^j*binomial(2*k, j)*(k - j)^(2*n))/k!;
    tabl(nn) = for (n=0, nn, for (k=0, n, print1(T(n,k), ", ")); print); \\ Michel Marcus, May 11 2018

Formula

T(n, k) = A304330(n, k) / k!.

A303675 Triangle read by rows: coefficients in the sum of odd powers as expressed by Faulhaber's theorem, T(n, k) for n >= 1, 1 <= k <= n.

Original entry on oeis.org

1, 6, 1, 120, 30, 1, 5040, 1680, 126, 1, 362880, 151200, 17640, 510, 1, 39916800, 19958400, 3160080, 168960, 2046, 1, 6227020800, 3632428800, 726485760, 57657600, 1561560, 8190, 1, 1307674368000, 871782912000, 210680870400, 22313491200, 988107120, 14217840, 32766, 1
Offset: 1

Views

Author

Kolosov Petro, May 08 2018

Keywords

Comments

T(n,k) are the coefficients in an identity due to Faulhaber: Sum_{j=0..n} j^(2*m-1) = Sum_{k=1..m} T(m,k) binomial(n+k, 2*k). See the Knuth reference, page 10.
More explicitly, Faulhaber's theorem asserts that, given integers n >= 0, m >= 1 and odd, Sum_{k=1..n} k^m = Sum_{k=1..(m+1)/2} C(n+k,n-k)*[(1/k)*Sum_{j=0..k-1} (-1)^j*C(2*k,j)*(k-j)^(m+1)]. The coefficients T(m, k) are indicated by square brackets. Sums similar to this inner part are A304330, A304334, A304336; however, these triangles are (0,0)-based and lead to equivalent but slightly more systematic representations. - Peter Luschny, May 12 2018

Examples

			The triangle begins (see the Knuth reference p. 10):
         1;
         6,          1;
       120,         30,         1;
      5040,       1680,       126,        1;
    362880,     151200,     17640,      510,       1;
  39916800,   19958400,   3160080,   168960,    2046,    1;
6227020800, 3632428800, 726485760, 57657600, 1561560, 8190, 1;
.
Let S(n, m) = Sum_{j=1..n} j^m. Faulhaber's formula gives for m = 7 (m odd!):
F(n, 7) = 5040*C(n+4, 8) + 1680*C(n+3, 6) + 126*C(n+2, 4) + C(n+1, 2).
Faulhaber's theorem asserts that for all n >= 1 S(n, 7) = F(n, 7).
If n = 43 the common value is 1600620805036.
		

References

  • John H. Conway and Richard Guy, The Book of Numbers, Springer (1996), p. 107.

Crossrefs

First column is a bisection of A000142, second column is a bisection of A001720.
Row sums give A100868.

Programs

  • Maple
    T := proc(n,k) local m; m := n-k;
    2*(2*m+1)!*add((-1)^(j+m)*(j+1)^(2*n)/((j+m+2)!*(m-j)!), j=0..m) end:
    seq(seq(T(n, k), k=1..n), n=1..8); # Peter Luschny, May 09 2018
  • Mathematica
    (* After Peter Luschny's above formula. *)
    T[n_, k_] := (1/(n-k+1))*Sum[(-1)^j*Binomial[2*(n-k+1), j]*((n-k+1) - j)^(2*n), {j, 0, n-k+1}]; Column[Table[T[n, k], {n, 1, 10}, {k, 1, n}], Center]
  • Sage
    def A303675(n, k): return factorial(2*(n-k)+1)*A008957(n, k)
    for n in (1..7): print([A303675(n, k) for k in (1..n)]) # Peter Luschny, May 10 2018

Formula

T(n, k) = (2*(n-k)+1)!*A008957(n, k), n >= 1, 1 <= k <= n.
T(n, k) = (1/m)*Sum_{j=0..m} (-1)^j*binomial(2*m,j)*(m-j)^(2*n) where m = n-k+1. - Peter Luschny, May 09 2018

Extensions

New name by Peter Luschny, May 10 2018

A385567 Triangle read by rows: T(n,k) is the numerator of A(n,k), such that A(n,k) satisfies the identity for sums of odd powers: Sum_{k=1..p} k^(2n-1) = 1/(2*n) * Sum_{k=0..n-1} A(n,k) * (p^2+p)^(n-k), for all integers p >= 1.

Original entry on oeis.org

1, 1, 1, 1, 0, -1, 1, -1, 0, 1, 1, -4, 2, 0, -1, 1, -5, 3, -3, 0, 5, 1, -4, 17, -10, 5, 0, -691, 1, -35, 287, -118, 691, -691, 0, 7, 1, -8, 112, -352, 718, -280, 140, 0, -3617, 1, -21, 66, -293, 4557, -3711, 10851, -10851, 0, 43867, 1, -40, 217, -4516, 2829, -26332, 750167, -438670, 219335, 0, -174611
Offset: 0

Views

Author

Kolosov Petro, Jul 31 2025

Keywords

Comments

The companion triangle with the denominators is A386728.
Extension of A093556 with k in the range 0 <= k <= n, and n >= 0.

Examples

			Triangle begins:
---------------------------------------------------------------------------------
k =   0    1     2     3     4       5       6        7       8      9      10
---------------------------------------------------------------------------------
n=0:  1;
n=1:  1,   1;
n=2:  1,   0,  -1;
n=3:  1,  -1,   0,     1;
n=4:  1,  -4,   2,     0,   -1;
n=5:  1,  -5,   3,    -3,    0,      5;
n=6:  1,  -4,  17,   -10,    5,      0,   -691;
n=7:  1, -35, 287,  -118,  691,   -691,      0,       7;
n=8:  1,  -8, 112,  -352,  718,   -280,    140,       0,  -3617;
n=9:  1, -21,  66,  -293, 4557,  -3711,  10851,  -10851,      0, 43867;
n=10: 1, -40, 217, -4516, 2829, -26332, 750167, -438670, 219335,     0, -174611;
...
		

Crossrefs

Programs

  • Mathematica
    FaulhaberCoefficient[n_, k_] := 0;
    FaulhaberCoefficient[n_, k_] := (-1)^(n - k) * Sum[Binomial[2 n, n - k - j]* Binomial[n - k + j, j] * (n - k - j)/(n - k + j) * BernoulliB[n + k + j], {j, 0, n - k}] /; 0 <= k < n;
    FaulhaberCoefficient[n_, k_] := BernoulliB[2 n] /; k == n;
    Flatten[Table[Numerator[FaulhaberCoefficient[n, k]], {n, 0, 10}, {k, 0, n}]]
  • PARI
    T(n,k) = numerator(if (k==n, bernfrac(2*n), if (kMichel Marcus, Aug 03 2025

Formula

A(n,k) = 0 if k>n or n<0
A(n,k) = (-1)^(n - k) * Sum_{j=0..n-k} binomial(2n, n - k - j) * binomial(n - k + j, j) * (n - k - j)/(n - k + j) * B_{n + k + j}, if 0 <= k < n;
A(n,k) = B_{2n}, if k = n;
T(n,k) = numerator(A(n,k)).

A386728 Triangle read by rows: T(n,k) is the denominator of A(n,k), such that A(n,k) satisfies the identity for sums of odd powers: Sum_{k=1..p} k^(2n-1) = 1/(2*n) * Sum_{k=0..n-1} A(n,k) * (p^2+p)^(n-k), for all integers p >= 1.

Original entry on oeis.org

1, 1, 6, 1, 1, 30, 1, 2, 1, 42, 1, 3, 3, 1, 30, 1, 2, 1, 2, 1, 66, 1, 1, 2, 1, 1, 1, 2730, 1, 6, 15, 3, 15, 30, 1, 6, 1, 1, 3, 3, 3, 1, 1, 1, 510, 1, 2, 1, 1, 5, 2, 5, 10, 1, 798, 1, 3, 2, 7, 1, 3, 42, 21, 21, 1, 330, 1, 2, 3, 2, 1, 6, 15, 3, 5, 10, 1, 138, 1
Offset: 0

Views

Author

Kolosov Petro, Jul 31 2025

Keywords

Comments

The companion triangle with the numerators is A385567.
Extension of A093557 with k in the range 0 <= k <= n.

Examples

			Triangle begins:
  ---------------------------------------------------------
  k =   0  1   2   3    4    5    6   7    8    9    10
  ---------------------------------------------------------
  n=0:  1;
  n=1:  1, 6;
  n=2:  1, 1, 30;
  n=3:  1, 2,  1, 42;
  n=4:  1, 3,  3,  1, 30;
  n=5:  1, 2,  1,  2,  1, 66;
  n=6:  1, 1,  2,  1,  1,  1, 2730;
  n=7:  1, 6, 15,  3, 15, 30,    1,  6;
  n=8:  1, 1,  3,  3,  3,  1,    1,  1, 510;
  n=9:  1, 2,  1,  1,  5,  2,    5, 10,   1, 798;
  n=10: 1, 3,  2,  7,  1,  3,   42, 21,  21,   1, 330;
  ...
		

Crossrefs

Programs

  • Mathematica
    FaulhaberCoefficient[n_, k_] := 0;
    FaulhaberCoefficient[n_, k_] := (-1)^(n - k) * Sum[Binomial[2 n, n - k - j]* Binomial[n - k + j, j] * (n - k - j)/(n - k + j) * BernoulliB[n + k + j], {j, 0, n - k}] /; 0 <= k < n;
    FaulhaberCoefficient[n_, k_] := BernoulliB[2 n] /; k == n;
    Flatten[Table[Denominator[FaulhaberCoefficient[n, k]], {n, 0, 10}, {k, 0, n}]]
  • PARI
    T(n,k) = denominator(if (k==n, bernfrac(2*n), if (kMichel Marcus, Aug 03 2025

Formula

A(n,k) = 0 if k>n or n<0;
A(n,k) = (-1)^(n - k) * Sum_{j=0..n-k} binomial(2n, n - k - j) * binomial(n - k + j, j) * (n - k - j)/(n - k + j) * B_{n + k + j}, if 0 <= k < n;
A(n,k) = B_{2n}, if k = n;
T(n,k) = denominator(A(n,k)).
Showing 1-6 of 6 results.