A356546 → basis A013609 → D

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(-4 - 4\,x + 8\,n + 8\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 4\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
144
2484896
34809604801920
444801344013440448035840
54032016128024192016128040320645120
6354816177408035481603548160177408035481611354112
7307507218450432461260806150144046126080184504323075072196804608
826357760184504320553512960922521600922521600553512960184504320263577603373793280
9224040960179232768062731468801254629376015682867200125462937606273146880179232768022404096057354485760
101891901440170271129606810845184015891972096023837958144023837958144015891972096068108451840170271129601891901440968653537280
1115891972096158919720960715138744320190703665152033373141401604004776968192333731414016019070366515207151387443201589197209601589197209616273379426304
121329146757121462061432832731030716416021930921492480438618429849606140658017894461406580178944438618429849602193092149248073103071641601462061432832132914675712272209255858176
13110762229760013291467571200731030716416002436769054720005482730373120008772368596992001023443002982400877236859699200548273037312000243676905472000731030716416001329146757120011076222976004536820930969600
149201785241600119623208140800717739248844800263171057909760065792764477440001184269760593920015790263474585600157902634745856001184269760593920065792764477440002631710579097600717739248844800119623208140800920178524160075381024699187200
Technical details
Node id
n-2701f545619cd5eb · 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): yes
  • Nonnegative coefficients (nonn): yes
  • 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:         4;
  2:        48,         48;
  3:       480,        960,        480;
  4:      4480,      13440,      13440,        4480;
  5:     40320,     161280,     241920,      161280,       40320;
  6:    354816,    1774080,    3548160,     3548160,     1774080,      354816;
  7:   3075072,   18450432,   46126080,    61501440,    46126080,    18450432,    3075072;
  8:  26357760,  184504320,  553512960,   922521600,   922521600,   553512960,  184504320,   26357760;
  9: 224040960, 1792327680, 6273146880, 12546293760, 15682867200, 12546293760, 6273146880, 1792327680, 224040960;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (8*n-4+(8*n-4)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 4.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 4;
P[n_, x_] := P[n, x] = Expand[Together[((8*n - 4 + (8*n - 4)*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] = 4; for(n = 2, N, my(i = n + 1); v[i] = ((8*n - 4 + (8*n - 4)*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. [LW07] Lily L. Liu and Yi Wang. A unified approach to polynomial sequences with only real zeros. Advances in Applied Mathematics, 38(4):542–560, May 2007. doi:10.1016/j.aam.2006.02.003
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.