A258758 → basis A013611

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-n + n^{2}\right)\,P_{n}(x) = \left(4 + 8\,x - 12\,n - 24\,n x + 8\,n^{2} + 16\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)
\(P_{1}(x) = 2 + 4\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1246
2124848108
3804809606402160
456044801344017920896045360
5403240320161280322560322560129024979776
6295683548161774080473088070963205677056189235221555072
7219648307507218450432615014401230028801476034569840230428114944480370176
8164736026357760184504320738017280184504320029520691202952069120168689664042172416010808328960
9124467202240409601792327680836419584025092587520501851750406691356672057354485760286772428806372720640244988789760
109459507218919014401702711296090811269120317839441920762814660608127135776768014529803059201089735229440484326768640968653537285585744406528
11722362368158919720961589197209609535183257603814073303040106794052485122135881049702430512586424320305125864243202034172428288081366897131521479398129664127964326404096
1255381114881329146757121462061432832974707621888043861842984960140357897551872327501760954368561431590207488701789487759360623812878008320374287726804992136104627929088226841046548482943179507294208
1342600857600110762229760013291467571200974707621888004873538109440001754473719398400467859658506240093571931701248001403578975518720015595321950208000124762575601664006805231396454400226841046548480034898622545920067919527091404800
143286351872009201785241600119623208140800956985665126400526342115819520021053684632780800631610538983424001443681231962112002526442155933696003368589541244928003368589541244928002449883302723584001224941651361792003769051234959360053843589070848001571851912686796800
Technical details
Node id
n-72bb2eae3768e77e · revision 0 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 (affine: slope 1, intercept 0)
  • 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:        1;
  1:        2,         4;
  2:       12,        48,         48;
  3:       80,       480,        960,        640;
  4:      560,      4480,      13440,      17920,        8960;
  5:     4032,     40320,     161280,     322560,      322560,      129024;
  6:    29568,    354816,    1774080,    4730880,     7096320,     5677056,     1892352;
  7:   219648,   3075072,   18450432,   61501440,   123002880,   147603456,    98402304,    28114944;
  8:  1647360,  26357760,  184504320,  738017280,  1845043200,  2952069120,  2952069120,  1686896640,   421724160;
  9: 12446720, 224040960, 1792327680, 8364195840, 25092587520, 50185175040, 66913566720, 57354485760, 28677242880, 6372720640;
%F Formula
The row polynomials satisfy (n^2-n)*P(n,x) = (8*n^2-12*n+4+(16*n^2-24*n+8)*x)*P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 2 + 4*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 2 + 4*x;
P[n_, x_] := P[n, x] = Expand[Together[((8*n^2 - 12*n + 4 + (16*n^2 - 24*n + 8)*x)*P[n - 1, x])/(n^2 - n)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; v[2] = 2 + 4*x; for(n = 2, N, my(i = n + 1); v[i] = ((8*n^2 - 12*n + 4 + (16*n^2 - 24*n + 8)*x)*v[i - 1])/(n^2 - n)); 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.