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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A269942 Triangle read by rows, the coefficients of the inverse partial P-polynomials.

Original entry on oeis.org

1, 0, -1, 0, -1, 1, 0, -2, 1, 2, -1, 0, -5, 5, -1, 5, -2, -3, 1, 0, -14, 21, -3, -6, 1, 14, -12, 2, -9, 3, 4, -1, 0, -42, 84, -28, -28, 7, 7, -1, 42, -56, 7, 14, -2, -28, 21, -3, 14, -4, -5, 1
Offset: 0

Views

Author

Peter Luschny, Mar 08 2016

Keywords

Comments

The triangle of coefficients of the partial P-polynomials is A269941. For the definition of the inverse partial P-polynomials see the link 'P-transform'.

Examples

			[[1]],
[[0], [-1]],
[[0], [-1], [1]],
[[0], [-2, 1], [2], [-1]],
[[0], [-5, 5, -1], [5, -2], [-3], [1]],
[[0], [-14, 21, -3, -6, 1], [14, -12, 2], [-9, 3], [4], [-1]],
[[0], [-42,84,-28,-28,7,7,-1],[42,-56,7,14,-2],[-28,21,-3],[14,-4],[-5],[1]]
Replacing the sublists by their sums reduces the triangle to a signed version of the triangle A097805. The column 1 of sublists is A111785 in a different order.
		

Crossrefs

Programs

  • Sage
    # For function PMultiCoefficients see A269941.
    PMultiCoefficients(7, inverse = True)

A356652 Triangle read by rows. Numerators of the coefficients of a sequence of rational polynomials r_n(x) with r_n(1) = B(2*n), where B(n) are the Bernoulli numbers.

Original entry on oeis.org

1, 0, 1, 0, 1, -1, 0, 1, -1, 5, 0, 1, -41, 14, -140, 0, 1, -23, 93, -40, 100, 0, 1, -157, 2948, -3652, 7700, -15400, 0, 1, -341, 18759, -1937936, 520520, -280280, 1401400, 0, 1, -1927, 3478, -7384676, 4364360, -1430000, 5605600, -8008000
Offset: 0

Views

Author

Peter Luschny, Sep 02 2022

Keywords

Examples

			The rational triangle R(n, k) begins:
[0] 1;
[1] 0,     1/6;
[2] 0,    1/70,      -1/21;
[3] 0,   1/434,      -1/31,       5/93;
[4] 0,  1/2286,   -41/1905,     14/127,  -140/1143;
[5] 0, 1/11242,   -23/1533,     93/511,     -40/73,   100/219;
[6] 0, 1/53222, -157/14329, 2948/10235, -3652/2047, 7700/2047, -15400/6141;
.
Row sums are: 1, 1/6, -1/30, 1/42, -1/30, 5/66, -691/2730, ... (A000367/A002445).
		

Crossrefs

Cf. A356653 (denominators), A269941, A000367, A002445.

Programs

  • Maple
    # Using function PTrans from A269941.
    R_row := n -> seq(coeffs(p), p in PTrans(n, n -> 1/((2*n)*(2*n + 1)),
    n -> (2*n)!/(2-2^(2*n)))): seq(seq(numer(r), r in R_row(n)), n = 0..8);

Formula

Let r_n(x) = ((2*n)! / (2-2^(2*n))) * Sum_{p in P_n} (-x)^(p_1) * binomial(p_1, p_2) * binomial(p_2, p_3) * ... * binomial(p_{n-1}, p_{n}) * (2*3)^(-p_1) * (4*5)^(-p_2) * ... * (2*n*(2*n+1))^(-p_n), where P_n are the partitions of n and we say that p is a partition of n if and only if p = (p_{1}, ..., p_{n}), the p_{i} are integers, Sum_{1<=i<=n} p_i = n and p_{1} >= p_{2} >= ... >= p_{n} >= 0.
T(n, k) = numerator([x^k] r_n(x)).

A356653 Triangle read by rows. Denominators of the coefficients of a sequence of rational polynomials r_n(x) with r_n(1) = B(2*n), where B(n) are the Bernoulli numbers.

Original entry on oeis.org

1, 1, 6, 1, 70, 21, 1, 434, 31, 93, 1, 2286, 1905, 127, 1143, 1, 11242, 1533, 511, 73, 219, 1, 53222, 14329, 10235, 2047, 2047, 6141, 1, 245730, 40955, 40955, 368595, 24573, 8191, 73719, 1, 1114078, 294903, 4681, 491505, 42129, 4681, 14043, 42129
Offset: 0

Views

Author

Peter Luschny, Sep 02 2022

Keywords

Comments

For formulas and comments see A356652.

Examples

			The triangle T(n, k) begins:
[0] 1;
[1] 1,     6;
[2] 1,    70,    21;
[3] 1,   434,    31,    93;
[4] 1,  2286,  1905,   127, 1143;
[5] 1, 11242,  1533,   511,   73,  219;
[6] 1, 53222, 14329, 10235, 2047, 2047, 6141;
		

Crossrefs

Cf. A356652 (numerators), A269941.

Programs

  • Maple
    # Using function PTrans from A269941.
    R_row := n -> seq(coeffs(p), p in PTrans(n, n -> 1/((2*n)*(2*n + 1)),
    n -> (2*n)!/(2-2^(2*n)))): seq(lprint(seq(denom(r), r in R_row(n))), n=0..9);

Formula

T(n, k) = denominator([x^k] r_n(x)), where the polynomials r_n(x) are defined in A356652.

A260533 Table of partition coefficients read by rows. The coefficient of a partition p is Product_{j=1..length(p)-1} C(p[j], p[j+1]). Row n lists the coefficients of the partitions of n in the ordering A080577, for n>=1.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 1, 2, 1, 1, 4, 3, 3, 2, 2, 1, 1, 5, 6, 4, 1, 6, 3, 1, 2, 2, 1, 1, 6, 10, 5, 4, 12, 4, 3, 3, 6, 3, 2, 2, 2, 1, 1, 7, 15, 6, 10, 20, 5, 1, 12, 6, 12, 4, 3, 3, 6, 6, 3, 1, 2, 2, 2, 1
Offset: 1

Views

Author

Peter Luschny, Jul 28 2015

Keywords

Comments

The triangle is a refinement of Pascal's triangle A007318.

Examples

			The signed version of the triangle starts:
[1]
[-1, 1]
[1, -2, 1]
[-1, 3, -1, -2, 1]
[1, -4, 3, 3, -2, -2, 1]
[-1, 5, -6, -4, 1, 6, 3, -1, -2, -2, 1]
Adding adjacent coefficients with equal sign reduces the triangle to the matrix inverse of Pascal's triangle (A130595).
.
The q-polynomials defined by Cigler start:
[0]  1;
[1]  1, q;
[2]  1, 2*q, q^3;
[3]  1, 3*q, q^2+2*q^3,   q^6;
[4]  1, 4*q, 3*q^2+3*q^3, 2*q^4+2*q^6,     q^10;
[5]  1, 5*q, 6*q^2+4*q^3, q^3+6*q^4+3*q^6, q^6+2*q^7+2*q^10, q^15;
		

Crossrefs

Cf. A007318, A080577, A130595, A269941 (expanded form).

Programs

  • Maple
    with(combstruct): with(ListTools):
    PartitionCoefficients := proc(n) local L, iter, p;
    iter := iterstructs(Partition(n)): L := []:
    while not finished(iter) do
       p := Reverse(nextstruct(iter)):
       L := [mul(binomial(p[j], p[j+1]), j=1..nops(p)-1), op(L)]
    od end:
    for n from 1 to 6 do PartitionCoefficients(n) od;
    # Alternative, using Cigler's recurrence for the q-polynomials:
    C := proc(n, k, q) local j;
    if k = 0 then q^binomial(n + 1, 2) elif n = 0 then n^k else
    add(q^binomial(j + 1, 2)*C(n - j - 1, k - 1, q), j = 0..n - k) fi end:
    p := n -> local k; add(C(n, n - k, q)*x^k, k = 0..n):
    row := n -> local k; seq(sort(coeff(expand(p(n)), x, k), [q], ascending), k=0..n):
    for n from 0 to 5 do row(n) od;  # Peter Luschny, Aug 24 2024
  • Sage
    PartitionCoeff = lambda p: mul(binomial(p[j], p[j+1]) for j in range(len(p)-1))
    PartitionCoefficients = lambda n: [PartitionCoeff(p) for p in Partitions(n)]
    for n in (1..7): print(PartitionCoefficients(n))

Formula

Let P = Partitions(n, k) denote the set of partitions p of n with largest part k. Then Sum_{p in P} PartitionCoefficient(p) = binomial(n-1,k-1) for n>=0 and k>=0 (assuming binomial(-1,-1) = 1).

A269943 Triangle read by rows, T(n,k) = ((-1)^k*(2*n)!/4^k)*P[n,k](1/((2*n-1)*(2*n))) where P is the inverse P-transform, for n>=0 and 0<=k<=n.

Original entry on oeis.org

1, 0, 1, 0, 2, 6, 0, 16, 60, 90, 0, 288, 1176, 2520, 2520, 0, 9216, 39360, 98280, 151200, 113400, 0, 460800, 2023296, 5504400, 10311840, 12474000, 7484400, 0, 33177600, 148442112, 426666240, 896575680, 1362160800, 1362160800, 681080400
Offset: 0

Views

Author

Peter Luschny, Mar 27 2016

Keywords

Comments

The P-transform is defined in the link. Compare also the Sage implementation below.

Examples

			Triangle starts:
[1]
[0, 1]
[0, 2, 6]
[0, 16, 60, 90]
[0, 288, 1176, 2520, 2520]
[0, 9216, 39360, 98280, 151200, 113400]
[0, 460800, 2023296, 5504400, 10311840, 12474000, 7484400]
		

Crossrefs

Programs

  • Sage
    # uses[PtransMatrix from A269941]
    eul = lambda n: 1/((2*n-1)*(2*n))
    norm = lambda n,k: (-1)^k*factorial(2*n)/4^k
    PtransMatrix(7, eul, norm, inverse=True)

Formula

T(n,1) = 2^(n-1)*(n-1)!^2 (cf. A055546) for n>=1.
T(n,n) = (2*n)!/2^n = A000680(n).

A356900 a(n) = P(n, 1/2) where P(n, x) = x^(-n)*Sum_{k=0..n} A241171(n, k)*x^k.

Original entry on oeis.org

1, 1, 8, 154, 5552, 321616, 27325088, 3200979664, 494474723072, 97390246272256, 23820397371219968, 7083386168647642624, 2516691244849530785792, 1052914814802404260765696, 512347915163742179541659648, 286902390859642414913802102784, 183187476890368376930869730803712
Offset: 0

Views

Author

Peter Luschny, Sep 03 2022

Keywords

Comments

Other special values of this Euler type polynomials are: P(n, -1) = A000364(n); P(n, -1/2) = A002105(n); P(n, 1) = A094088(n), where we always make the assumption that the offset of the sequences is 0. A partition refinement of Joffe's triangle A241171 is A327022.

Crossrefs

Programs

  • Maple
    a := n -> 2^n*add(A241171(n, k)*(1/2)^k, k = 0..n):
    seq(a(n), n = 0..16);
  • SageMath
    # Using function PtransMatrix from A269941.
    def E(n, v):
        eulr = lambda n: 1 / ((2 * n - 1) * (2 * n))
        norm = lambda n, k: (1 / v)^n * factorial(2 * n)
        P = PtransMatrix(n, eulr, norm)
        return [(-1)^j * sum([v^k * P[j][k] for k in range(j + 1)]) for j in range(n)]
    A356900List = lambda n: E(n, -1/2); print(A356900List(17))
    # A002105List = lambda n: E(n, 1/2) returns the reduced tangent numbers A002105.
Previous Showing 11-16 of 16 results.