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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A375251 Denominators of the polynomials A375252 (polynomial part of the partition function restricted to partitions of the integer x with parts in (1,2,...,n)).

Original entry on oeis.org

1, 4, 72, 288, 86400, 1036800, 152409600, 1219276800, 438939648000, 26336378880000, 6373403688960000, 229442532802560000, 2714305163054284800000, 228001633696559923200000, 3420024505448398848000000, 164161176261523144704000000, 759081279033283021111296000000
Offset: 1

Views

Author

Peter Luschny, Aug 07 2024

Keywords

Crossrefs

Cf. A375252 (numerators), A375250.

Programs

  • Maple
    read(PARTITIONS):  # See the Sills & Zeilberger paper cited in A375252.
    seq(denom(op(pmnPC(n,x)[1])), n = 1..17);
    # Or, standalone:
    W := proc(n) local k; exp(t*x)/mul(1 - exp(-t*k), k=1..n);
    expand(series(%, t, n+1)); coeff(%, t, -1) end:
    a := n -> denom(W(n)): seq(a(n), n = 1..17);

Formula

(Sum_{k=0..n-1} A375252(n, k)*x^k) / a(n) = W1([n], x), where W1([n], x) denotes the first Sylvester wave restricted to parts in [n].
a(n) = denominator(W(n)) where W(n) = [t^(-1)] exp(t*x)/Product_{k=1..n}(1 - exp(-t*k)).
a(n) = A375250(n)*n!*(n - 1)!.

A375252 First Sylvester wave. Triangle read by rows: Coefficients of the numerator of the polynomial part of the partition function restricted to partitions of the integer x with parts in (1,2,...,n). (The denominators are A375251.)

Original entry on oeis.org

1, 3, 2, 47, 36, 6, 175, 135, 30, 2, 50651, 38250, 9300, 900, 30, 598731, 439810, 110250, 12320, 630, 12, 87797891, 62748420, 15840279, 1893360, 116130, 3528, 42, 706078278, 492161075, 123824862, 15302301, 1031940, 38682, 756, 6
Offset: 1

Views

Author

Peter Luschny, Aug 07 2024

Keywords

Examples

			Triangle starts:
  [1]         1;
  [2]         3,         2;
  [3]        47,        36,         6;
  [4]       175,       135,        30,        2;
  [5]     50651,     38250,      9300,      900,      30;
  [6]    598731,    439810,    110250,    12320,     630,    12;
  [7]  87797891,  62748420,  15840279,  1893360,  116130,  3528,  42;
  [8] 706078278, 492161075, 123824862, 15302301, 1031940, 38682, 756, 6;
.
Let A = ((a + b + c)^2 + (b*c) + (a*c) + (a*b))/6; B = a + b + c; C = 1 and W1 = (A + B*x + C*x^2)/(2*a*b*c). If (a, b, c) = (1, 2, 3) then W1([3], x) = (47 + 36*x + 6*x^2)/72. (See formulas (35), (37) and Fig. 2 in Dilcher & Vignat.)
		

Crossrefs

Cf. A375251 (denominators), A375250 (main diagonal).

Programs

  • Maple
    read(PARTITIONS):  # See Sills & Zeilberger paper.
    FirstWave := proc(n) op(pmnPC(n, x)[1]); %*denom(%) end:
    seq(print(seq(coeff(FirstWave(n), x, k), k = 0..n-1)), n = 1..9);
    # Or, standalone:
    W := proc(n) local k; exp(t*x)/mul(1 - exp(-t*k), k=1..n);
    expand(series(%, t, n+1)); coeff(%, t, -1); %*denom(%) end:
    Trow := n -> local k; seq(coeff(W(n), x, k), k = 0..n-1):
    seq(print(Trow(n)), n = 1..8);

Formula

(1/A375251(n)) * Sum_{k=0..n-1} T(n, k)*x^k = W1([n], x), where W1([n], x) denotes the first Sylvester wave restricted to parts in [n].
T(n, k) = [x^k] p(n) where p(n) = W(n)*denominator(W(n)) and W(n) = [t^(-1)] exp(t*x)/Product_{k=1..n}(1 - exp(-t*k)).
Showing 1-2 of 2 results.