A085880 → D → basis A007318

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernelinterlacing (weak)

Recurrence

\(\left(-2\,n + n^{2}\right)\,P_{n}(x) = \left(12 + 6\,x - 20\,n - 10\,n x + 8\,n^{2} + 4\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 0\)
\(P_{2}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
10
211
38412
4606015135
5448672336561512
6336067205040168021017010
7253446336063360316807920792192456
81921925765767207204804801801803603630032189187
9146432051251207687680640640032032009609601601601144025019280
10112020484480819278414336784143364900896019603584490089670012843758287096238
11859955203869798407739596809029529606772147203386073601128691202418624030232801679603305956680
126621655043310827520744936192099324825608690922240521455334421727305606207801601163962801293292064664638183799654
13511210291228116566016702914150401054371225601054371225607380598579236902992896131796403203294910080549151680549151682496144442184421168
1439557939200237347635200652705996800108784332800012238237440009790589952005711177472002447647488007648898400016997552000254963280023178480096577005132497745700
153067261747201993720135680598116040704010965460746240137068259328001233614333952082240955596804112047779840154201791744042833831040085667662080116819539209734961603744216059694896857680
Technical details
Node id
n-c997246ba459ce1a · revision 0 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-11aec07ce60b6d61

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,        4;
   4:       60,       60,       15;
   5:      448,      672,      336,       56;
   6:     3360,     6720,     5040,     1680,      210;
   7:    25344,    63360,    63360,    31680,     7920,      792;
   8:   192192,   576576,   720720,   480480,   180180,    36036,    3003;
   9:  1464320,  5125120,  7687680,  6406400,  3203200,   960960,  160160,  11440;
  10: 11202048, 44808192, 78414336, 78414336, 49008960, 19603584, 4900896, 700128, 43758;
%F Formula
The row polynomials satisfy (n^2-2*n)*P(n,x) = (8*n^2-20*n+12+(4*n^2-10*n+6)*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 + (4*n^2 - 10*n + 6)*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 + (4*n^2 - 10*n + 6)*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.