basis-map coefficients of A113214, shifted → D → D+1

only rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
1-1-1
2426
3-9-12-3-24
4163624480
5-25-80-90-40-5-240
636150240180606672
7-49-252-525-560-315-84-7-1792
86439210081400112050411284608
9-81-576-1764-3024-3150-2016-756-144-9-11520
101008102880588075606300336010801801028160
11-121-1100-4455-10560-16170-16632-11550-5280-1485-220-11-67584
121441452660017820316803880833264198007920198026412159744
13-169-1872-9438-28600-57915-82368-84084-61776-32175-11440-2574-312-13-372736
14196236613104440441001001621621921921681681081085005016016327636414860160
Technical details
Node id
n-8d978a50d5958248 · revision 0 · JSON
Definition source
derived:one_plus_derivative
Fingerprint
f6-e99c3824c4864868

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:  -9,  -12,    -3;
  4:  16,   36,    24,     4;
  5: -25,  -80,   -90,   -40,    -5;
  6:  36,  150,   240,   180,    60,     6;
  7: -49, -252,  -525,  -560,  -315,   -84,   -7;
  8:  64,  392,  1008,  1400,  1120,   504,  112,    8;
  9: -81, -576, -1764, -3024, -3150, -2016, -756, -144, -9;
%F Formula
The row polynomials satisfy (n^2-2*n+1+(n-1)*x)*P(n,x) = -(n^2+(n^2+n)*x+n*x^2)*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[(-(n^2 + (n^2 + n)*x + n*x^2)*P[n - 1, x])/(n^2 - 2*n + 1 + (n - 1)*x)]];
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] = (-(n^2 + (n^2 + n)*x + n*x^2)*v[i - 1])/(n^2 - 2*n + 1 + (n - 1)*x)); 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.