A135089 → basis A013611

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1102030
2208080180
3402404803201080
4806401920256012806480
5160160064001280012800512038880
632038401920051200768006144020480233280
7640896053760179200358400430080286720819201399680
812802048014336057344014336002293760229376013107203276808398080
9256046080368640172032051609601032192013762560117964805898240131072050388480
10512010240092160049152001720320041287680688128007864320058982400262144005242880302330880
111024022528022528001351680054067200151388160302776320432537600432537600288358400115343360209715201813985280
1220480491520540672036044800162201600519045120121110528020761804802595225600230686720013841203205033164808388608010883911680
1340960106496012779520937164804685824001686896640449839104089967820801349517312014994636800119957094406543114240218103808033554432065303470080
1481920229376029818880238551040131203072052481228801574436864035987128320629774745608396996608083969966080610690662403053453312093952409601342177280391820820480
Technical details
Node id
n-c5f633c08731c6c1 · 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:   10,    20;
  2:   20,    80,     80;
  3:   40,   240,    480,     320;
  4:   80,   640,   1920,    2560,    1280;
  5:  160,  1600,   6400,   12800,   12800,     5120;
  6:  320,  3840,  19200,   51200,   76800,    61440,    20480;
  7:  640,  8960,  53760,  179200,  358400,   430080,   286720,    81920;
  8: 1280, 20480, 143360,  573440, 1433600,  2293760,  2293760,  1310720,  327680;
  9: 2560, 46080, 368640, 1720320, 5160960, 10321920, 13762560, 11796480, 5898240, 1310720;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n-2+(4*n-4)*x)*P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 10 + 20*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 10 + 20*x;
P[n_, x_] := P[n, x] = Expand[Together[((2*n - 2 + (4*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] = 1; v[2] = 10 + 20*x; for(n = 2, N, my(i = n + 1); v[i] = ((2*n - 2 + (4*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.