A085880 → D → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-2\,n + n^{2}\right)\,P_{n}(x) = \left(12 + 18\,x - 20\,n - 30\,n x + 8\,n^{2} + 12\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 0\)
\(P_{2}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
10
211
381220
460180135375
54482016302415127000
6336020160453604536017010131250
7253441900805702408553606415201924562475000
81921921729728648648012972960145945808756748218918746921875
91464320153753606918912017297280025945920023351328011675664025019280893750000
10112020481344245767057290242117187072396972576047636709123572753184153117993628709623817092968750
1185995520116093952069656371202437972992054854392320822815884808228158848052895306880198357400803305956680328046875000
12662165504993248256067044257280268177029120703964701440126713646259215839205782401357646209920763675993080254558664360381837996546314902343750
135112102912843496980486326227353602846802309120854040692736017934854547456269022818211842882387337984021617905034880108089525174403242685755232442184421168121882031250000
1439557939200712042905600587435397120029371769856000991297232640002379113358336004163448377088005353005056256005018442240240003345628160160001505532672072004105998196560051324977457002357836914062500
153067261747205981160407040538304436633602960674401484801110252900556800299768283150336059953656630067208993048494510080101171795563238408430982963603200505858977816192020694230910662405173557727665605969489685768045705761718750000
Technical details
Node id
n-4c96f2a62fa07a0c · revision 0 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-f06e51c139cfae05

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 -2)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:        0;
   2:        1;
   3:        8,        12;
   4:       60,       180,       135;
   5:      448,      2016,      3024,       1512;
   6:     3360,     20160,     45360,      45360,      17010;
   7:    25344,    190080,    570240,     855360,     641520,     192456;
   8:   192192,   1729728,   6486480,   12972960,   14594580,    8756748,    2189187;
   9:  1464320,  15375360,  69189120,  172972800,  259459200,  233513280,  116756640,   25019280;
  10: 11202048, 134424576, 705729024, 2117187072, 3969725760, 4763670912, 3572753184, 1531179936, 287096238;
%F Formula
The row polynomials satisfy (n^2-2*n)*P(n,x) = (8*n^2-20*n+12+(12*n^2-30*n+18)*x)*P(n-1,x) for n >= 3, with P(1,x) = 0, P(2,x) = 1.
%t Mathematica
P[1, x_] := 0;
P[2, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((8*n^2 - 20*n + 12 + (12*n^2 - 30*n + 18)*x)*P[n - 1, x])/(n^2 - 2*n)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 0; v[2] = 1; for(n = 3, N, my(i = n); v[i] = ((8*n^2 - 20*n + 12 + (12*n^2 - 30*n + 18)*x)*v[i - 1])/(n^2 - 2*n)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

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.