basis-map coefficients of A030528, shifted → basis A013610 → D

only rational roots

Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(-n - 3\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = -3\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
1-3-3
261824
3-9-54-81-144
412108324324768
5-15-180-810-1620-1215-3840
618270162048607290437418432
7-21-378-2835-11340-25515-30618-15309-86016
8245044536226806804012247212247252488393216
9-27-648-6804-40824-153090-367416-551124-472392-177147-1769472
10308109720680403061809185401837080236196017714705904907864320
11-33-990-13365-106920-561330-2020788-5051970-8660520-9743085-6495390-1948617-34603008
1236118817820160380962280404157612124728259815603897234038972340233834046377292150994944
13-39-1404-23166-231660-1563705-7505784-26270244-67552056-126660105-168880140-151992126-82904796-20726199-654311424
144216382948432432424324301313512252540488157621464354648294591080490709296588580333572290166786669615662818572288
Technical details
Node id
n-45bc54c13fcaa201 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-f9762973ec1089d7

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:  -3;
  2:   6,   18;
  3:  -9,  -54,   -81;
  4:  12,  108,   324,    324;
  5: -15, -180,  -810,  -1620,   -1215;
  6:  18,  270,  1620,   4860,    7290,    4374;
  7: -21, -378, -2835, -11340,  -25515,  -30618,  -15309;
  8:  24,  504,  4536,  22680,   68040,  122472,  122472,   52488;
  9: -27, -648, -6804, -40824, -153090, -367416, -551124, -472392, -177147;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = -(n+3*n*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = -3.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := -3;
P[n_, x_] := P[n, x] = Expand[Together[(-(n + 3*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] = -3; for(n = 2, N, my(i = n + 1); v[i] = (-(n + 3*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.