A085880 → basis A013610 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-2\,n + n^{2}\right)\,P_{n}(x) = \left(12 + 18\,x - 20\,n - 30\,n x + 8\,n^{2} + 12\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 0\)
\(P_{2}(x) = 3\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
10
233
3243660
41805404051125
5134460489072453621000
6100806048013608013608051030393750
7760325702401710720256608019245605773687425000
85765765189184194594403891888043783740262702446567561140765625
9439296046126080207567360518918400778377600700539840350269920750578402681250000
103360614440327372821171870726351561216119091772801429101273610718259552459353980886128871451278906250
1125798656034828185602089691136073139189760164563176960246844765440246844765440158685920640595072202409917870040984140625000
121986496512297974476802011327718408045310873602111894104320380140938777647517617347204072938629760229102797924076367599308011455139896218944707031250
13153363087362530490941441897868206080854040692736025621220782080538045636423688070684546355286471620139520648537151046403242685755232097280572656961326553263504365646093750000
14118673817600213612871680017623061913600881153095680002973891697920007137340075008001249034513126400160590151687680015055326720720001003688448048000451659801621600123179945896800153974932371007073510742187500
159201785241601794348122112016149133099008088820232044544033307587016704008993048494510080179860969890201602697914548353024030351538668971520252929488908096001517576933448576062082692731987201552067318299680179084690573040137117285156250000
Technical details
Node id
n-0e1cd9b68048734e · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-f06e51c139cfae05

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 -2)
  • 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:        0;
   2:        3;
   3:       24,        36;
   4:      180,       540,        405;
   5:     1344,      6048,       9072,       4536;
   6:    10080,     60480,     136080,     136080,       51030;
   7:    76032,    570240,    1710720,    2566080,     1924560,      577368;
   8:   576576,   5189184,   19459440,   38918880,    43783740,    26270244,     6567561;
   9:  4392960,  46126080,  207567360,  518918400,   778377600,   700539840,   350269920,   75057840;
  10: 33606144, 403273728, 2117187072, 6351561216, 11909177280, 14291012736, 10718259552, 4593539808, 861288714;
%F Formula
The row polynomials satisfy (n^2-2*n)*P(n,x) = (8*n^2-20*n+12+(12*n^2-30*n+18)*x)*P(n-1,x) for n >= 3, with P(1,x) = 0, P(2,x) = 3.
%t Mathematica
P[1, x_] := 0;
P[2, x_] := 3;
P[n_, x_] := P[n, x] = Expand[Together[((8*n^2 - 20*n + 12 + (12*n^2 - 30*n + 18)*x)*P[n - 1, x])/(n^2 - 2*n)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 0; v[2] = 3; for(n = 3, N, my(i = n); v[i] = ((8*n^2 - 20*n + 12 + (12*n^2 - 30*n + 18)*x)*v[i - 1])/(n^2 - 2*n)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

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.