A178821 → basis A013611 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(8 + 16\,x + 2\,n + 4\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 20\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
12020
2240480720
316806720672015120
489605376010752071680241920
54032032256096768012902406451203265920
6161280161280064512001290240012902400516096039191040
75913607096320354816009461760014192640011354112037847040431101440
8202752028385280170311680567705600113541120013624934409083289602595225604434186240
965894401054310407380172802952069120738017280011808276480118082764806747586560168689664043233315840
10205004803690086402952069120137763225604132896768082657935360110210580480944662118404723310592010496245760403510947840
116150144012300288001107025920059041382400206644838400495947612160826579353600944662118400708496588800314887372800629774745603631598530560
1217891328039360921603936092160023616552960094466211840026450539315205290107863040755729694720075572969472005038197964800201527918592036641439744031693950812160
13506920960121661030401338271334408921808896004014814003200128474048102402997727789056051389619240960642370240512005709957693440034259746160640124580895129602076348252160269398581903360
141403781120364983091204379797094403211851202560160592560128005781332164608015416885772288030833771544576046250657316864051389619240960041111695392768022424561123328074748537077760114997749350402238080526581760
Technical details
Node id
n-9fbed2f13913339a · revision 0 · JSON
Definition source
derived:derivative
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 -1)
  • 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 = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:       0;
  1:      20;
  2:     240,       480;
  3:    1680,      6720,      6720;
  4:    8960,     53760,    107520,      71680;
  5:   40320,    322560,    967680,    1290240,     645120;
  6:  161280,   1612800,   6451200,   12902400,   12902400,     5160960;
  7:  591360,   7096320,  35481600,   94617600,  141926400,   113541120,    37847040;
  8: 2027520,  28385280, 170311680,  567705600, 1135411200,  1362493440,   908328960,  259522560;
  9: 6589440, 105431040, 738017280, 2952069120, 7380172800, 11808276480, 11808276480, 6747586560, 1686896640;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n+8+(4*n+16)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 20.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 20;
P[n_, x_] := P[n, x] = Expand[Together[((2*n + 8 + (4*n + 16)*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] = 20; for(n = 2, N, my(i = n + 1); v[i] = ((2*n + 8 + (4*n + 16)*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.