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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A324253 Partition array giving in row n, for n >= 1, the coefficients of the Witt symmetric function w_n, multiplied by n!, in terms of the power sum symmetric functions (using partitions in the Abramowitz-Stegun order).

Original entry on oeis.org

1, 1, -1, -2, 0, -2, 6, 0, -3, 6, -9, 24, 0, 0, 0, 0, 0, -24, 120, 0, 0, -40, 0, 0, -30, 80, 90, -90, -130, 720, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -720, 5040, 0, 0, 0, -1260, 0, 0, 0, 1260, 0, 0, 2520, 3780, 0, -945, 3780, 0, 0, 0, -6930, 6300, -8505
Offset: 1

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Author

Wolfdieter Lang, Jun 05 2019

Keywords

Comments

The length of row n is A000041(n).
The (one part) Witt symmetric function w_n is defined in the links below. One should add w_0 = 1. It can be expressed in terms of the power sum symmetric functions p_k = Sum_{i>=1} (x_i)^k for the indeterminates {x_i}, by using the recurrence w_n = (1/n)*(p_n - Sum_{d|n,1 <= d < n} d*(w_d)^{n/d}), n >= 2, with w_1 = p_1.
In order to have integer coefficients n!*w_n is considered, and terms are listed in the Abramowitz-Stegun order (with rising number of parts).
A logarithmic generating function of the power sums is related to the {w_n}{n>=1} sequence by Lp(t) := -Sum{j>=1} p_j*(t^j)/j = log(Product_{n>=0} (1 - w_n*t^n)). See the links.
If only N indeterminates {x_i}_{i=1..N} are considered all coefficients corresponding to partitions with at least one part > N are set to 0 (in addition to the ones given in the sequence).

Examples

			The irregular triangle (partition array) begins:
n\k    1  2  3   4  5  6   7   8   9  10   11 12 13 14  15  ...
---------------------------------------------------------------
1:     1
2:     1 -1
3:    -2  0 -2
4:     6  0 -3   6 -9
5:    24  0  0   0  0  0 -24
6:   120  0  0 -40  0  0 -30  80  90 -90 -130
7:   720  0  0   0  0  0   0   0   0   0    0  0  0  0 -720
...
n = 8:  5040 0 0 0 -1260 0 0 0 1260 0 0 2520 3780 0 -945 3780 0 0 0 -6930 6300 -8505;
n = 9: 40320 0 0 0 0 0 0 0 0 0 0 -4480 0 0 0 0 0 0 0 0 13440 0 0 0 0 0 -13440 0 0 -35840;
n = 10: 362880 0 0 0 0 -725760 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -22680 145152 0 0 0 113400 0 0 -226800 0 226800 -113400 -412776;
...
---------------------------------------------------------------
w_1 = p_1;
w_2 = (1/2)*(p_2 - (p_1)^2);
w_3 = (1/3!)*(2*p_3 + 0 - 2*(p_1)^3);
w_4 = (1/4!)*(6*p_4 + 0 - 3*(p_2)^2 + 6*(p_1)^2*p_2 - 9*(p_1)^4);
w_5 = (1/5!)*(24*p_5 + 0 + 0 + 0 + 0 + 0 - 24*(p_1)^5) = (1/5)*(p_5 - (p_1)^5);
w_6 = (1/6!)*(120*p_6 + 0 + 0 - 40*(p_3)^2 + 0 + 0 - 30*(p_2)^3 + 80*(p_1)^3*p_3 + 90*(p_1)^2*(p_2)^2 - 90*(p_1)^4*p_2 - 130*(p_1)^6)
  = (1/72)*(12*p_6 - 4*(p_3)^2 - 3*(p_2)^3 + 8*(p_1)^3*p_3 + 9*(p_1)^2*(p_2)^2 -   9*(p_1)^4*p_2 - 13*(p_1)^6);
...
---------------------------------------------------------------
		

Crossrefs

Cf. A000041, A115131 (Waring numbers), A324247.

Formula

w_n is given by the recurrence given in the comment above in terms of the power sum symmetric functions {p_i}_{i>=1}, for n >= 1.
T(n, k) gives the coefficient of (p_1)^{a(1,k)}*...*(p_n)^{a(n,k)} for n!*w_n, corresponding to the k-th partition of n in Abramowitz-Stegun order, written as 1^{a(1,k)}*...*n^{a(n,k)}, with nonnegative integers a(n,j) satisfying Sum_{j=1..n} j*a(n,j) = n. The number of parts is Sum_{j=1..n} a(n,k) =: m(k).
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