basis-map coefficients of A113214, shifted → basis A013609 → D

palindromiconly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6Pn(1)
00
1-2-2
28816
3-24-48-24-96
46419219264512
5-160-640-960-640-160-2560
6384192038403840192038412288
7-896-5376-13440-17920-13440-5376-896-57344
Technical details
Node id
n-311719c77b4e8a80 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-77a7ed3b1d5f257e

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: yes
  • 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:    -2;
  2:     8,      8;
  3:   -24,    -48,     -24;
  4:    64,    192,     192,      64;
  5:  -160,   -640,    -960,    -640,    -160;
  6:   384,   1920,    3840,    3840,    1920,     384;
  7:  -896,  -5376,  -13440,  -17920,  -13440,   -5376,    -896;
  8:  2048,  14336,   43008,   71680,   71680,   43008,   14336,   2048;
  9: -4608, -36864, -129024, -258048, -322560, -258048, -129024, -36864, -4608;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = -(2*n+2*n*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = -2.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := -2;
P[n_, x_] := P[n, x] = Expand[Together[(-(2*n + 2*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] = -2; for(n = 2, N, my(i = n + 1); v[i] = (-(2*n + 2*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.