A178821 → basis A007318 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(8 + 4\,x + 2\,n + n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 5\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
155
2603090
3420420105945
42240336016802807560
5100802016015120504063051030
64032010080010080050400126001260306180
71478404435205544003696001386002772023101683990
850688017740802661120221760011088003326405544039608660520
916473606589440115315201153152072072002882880720720102960643542220035
10512512023063040461260805381376040360320201801606726720144144018018010010197026830
1115375360768768001729728002306304002018016001210809605045040014414400270270030030015015886620735
1244728320246005760615014400922521600922521600645765120322882560115315200288288004804800480480218403868890480
13126730240760381440209104896034850816003920716800313657344018296678407841433602450448005445440081681607425603094016442784540
1435094528022811443206843432960125462937601568286720014114580480940972032047048601601764322560490089600980179201336608011138404284068300797320
Technical details
Node id
n-0e583ea589690e69 · 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:       5;
  2:      60,      30;
  3:     420,     420,      105;
  4:    2240,    3360,     1680,      280;
  5:   10080,   20160,    15120,     5040,     630;
  6:   40320,  100800,   100800,    50400,   12600,    1260;
  7:  147840,  443520,   554400,   369600,  138600,   27720,   2310;
  8:  506880, 1774080,  2661120,  2217600, 1108800,  332640,  55440,   3960;
  9: 1647360, 6589440, 11531520, 11531520, 7207200, 2882880, 720720, 102960, 6435;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n+8+(n+4)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 5.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 5;
P[n_, x_] := P[n, x] = Expand[Together[((2*n + 8 + (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] = 0; v[2] = 5; for(n = 2, N, my(i = n + 1); v[i] = ((2*n + 8 + (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.