A178820 → basis A013611 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
116824
216016040360
3128019209601604320
489601792013440448056045360
55734414336014336071680179201792435456
6344064103219212902408601603225606451253763919104
719660806881280103219208601600430080012902402150401536033592320
8108134404325376075694080756940804730880018923520473088067584042240277136640
957671680259522560519045120605552640454164480227082240756940801622016020275201126402217093120
102998927361499463680337379328044983910403936092160236165529698402304028114944052715520585728029286417293326336
11152672665683969966082099249152031488737280314887372802204211609611021058048393609216098402304016400384016400384745472132058128384
1276336332804580179968012595494912020992491520023616552960018893242368011021058048047233105920147603456003280076800492011520447283201863680990435962880
133758096384024427626496073282879488013435194572801679399321600151145938944010076395929605038197964801889324236805248122880010496245760143130624011927552045875207313988648960
1418253611008012777527705604152696504320830539300864011419915386880114199153868808564936540160489424945152021412341350407137447116801784361779203244294144040553676803119513601114112053287631585280
Technical details
Node id
n-a43ddbc0e3e9110d · revision 0 · JSON
Definition source
derived:shift_x_plus_one
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:       16,         8;
  2:      160,       160,        40;
  3:     1280,      1920,       960,       160;
  4:     8960,     17920,     13440,      4480,       560;
  5:    57344,    143360,    143360,     71680,     17920,      1792;
  6:   344064,   1032192,   1290240,    860160,    322560,     64512,     5376;
  7:  1966080,   6881280,  10321920,   8601600,   4300800,   1290240,   215040,    15360;
  8: 10813440,  43253760,  75694080,  75694080,  47308800,  18923520,  4730880,   675840,   42240;
  9: 57671680, 259522560, 519045120, 605552640, 454164480, 227082240, 75694080, 16220160, 2027520, 112640;
%F Formula
The row polynomials satisfy n*P(n,x) = (4*n+12+(2*n+6)*x)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((4*n + 12 + (2*n + 6)*x)*P[n - 1, x])/(n)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = ((4*n + 12 + (2*n + 6)*x)*v[i - 1])/(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.