basis-map coefficients of A113214, shifted → D → basis A007318

only rational roots

Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernelinterlacing (weak)

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(-2\,n - n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = -1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
1-1-1
2426
3-12-12-3-27
43248244108
5-80-160-120-40-5-405
61924804802406061458
7-448-1344-1680-1120-420-84-7-5103
810243584537644802240672112817496
9-2304-9216-16128-16128-10080-4032-1008-144-9-59049
10512023040460805376040320201606720144018010196830
11-11264-56320-126720-168960-147840-88704-36960-10560-1980-220-11-649539
122457613516833792050688050688035481617740863360158402640264122125764
13-53248-319488-878592-1464320-1647360-1317888-768768-329472-102960-22880-3432-312-13-6908733
141146887454722236416410009651251204612608307507215375365765761601603203243683641422320522
Technical details
Node id
n-0cf41fd0b9103ec6 · revision 0 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (affine: slope 1, intercept -1)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • Nonnegative coefficients (nonn): no
  • Only rational roots (rr_by_factors: every nonzero row is a product of linear factors over ℚ): yes

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:     0;
  1:    -1;
  2:     4,     2;
  3:   -12,   -12,     -3;
  4:    32,    48,     24,      4;
  5:   -80,  -160,   -120,    -40,     -5;
  6:   192,   480,    480,    240,     60,     6;
  7:  -448, -1344,  -1680,  -1120,   -420,   -84,    -7;
  8:  1024,  3584,   5376,   4480,   2240,   672,   112,    8;
  9: -2304, -9216, -16128, -16128, -10080, -4032, -1008, -144, -9;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = -(2*n+n*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = -1.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := -1;
P[n_, x_] := P[n, x] = Expand[Together[(-(2*n + n*x)*P[n - 1, x])/(n - 1)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = -1; for(n = 2, N, my(i = n + 1); v[i] = (-(2*n + n*x)*v[i - 1])/(n - 1)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i - 1, v[i])))};
T(9)

polytool c48629374597

Properties

Proof chains ? JSON

Same fingerprint ?

References

  1. [Bra06] Petter Brändén. On linear transformations preserving the Pólya frequency property. Transactions of the American Mathematical Society, 358(8):3697–3716, February 2006. doi:10.1090/s0002-9947-06-03856-6
  2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  3. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.