A356546 → basis A013611 → x ↦ x/(x+1)

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in [−1, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(n + n x\right)\,P_{n}(x) = \left(-4 - 16\,x - 12\,x^{2} + 8\,n + 32\,n x + 24\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
141216
224144216384
316014404320432010240
41120134406048012096090720286720
580641209607257602177280326592019595528257536
6591361064448798336031933440718502408622028843110144242221056
74392969225216830269444151347201245404160224172748822417274889607403527197425664
832947207907328083026944049816166401868106240044834549760672518246405764442112021616657920215922769920
9248934406721228808065474560564583219202540624486407621873459201524374691840195991031808014699327385604899775795206525665935360
101891901445675704320766220083206129760665603218124349440115852476579842896311914496049651061391360558574440652803723829604352011171488813056198380244434944
111444724736476759162887151387443206436248698880386174921932801621934672117764865804016353281042672289218560156400843382784015640084338278409384050602967042559286528081926059614739103744
12110762229763987440271366579276447744657927644774404441011602227202131685569069056746089949174169619185170121621504359721939780403204796292530405376043166632773648384235454360583536645886359014588416185828185332514816
13852017152003322866892800598116040704006579276447744004934457335808000266460696133632001065842784534528003197528353603584007194438795608064001199073132601344000143888775912161280011772718029176832005886359014588416001358390541828096005717790317923532800
1465727037440027605355724800538304436633600645965323960320053292139226726400319752835360358400143888775912161280049333294598455296001294998983209451520025899979664189030400388499694962835456004238178490503659520031786338678777446400146706178517434368003143703825373593600176434672667354726400
Technical details
Node id
n-ade3cf4243d09b7b · revision 0 · JSON
Definition source
derived:mobius_x_over_x_plus_one
Fingerprint
f6-f9762973ec1089d7

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:        4,        12;
  2:       24,       144,        216;
  3:      160,      1440,       4320,        4320;
  4:     1120,     13440,      60480,      120960,        90720;
  5:     8064,    120960,     725760,     2177280,      3265920,      1959552;
  6:    59136,   1064448,    7983360,    31933440,     71850240,     86220288,      43110144;
  7:   439296,   9225216,   83026944,   415134720,   1245404160,   2241727488,    2241727488,     960740352;
  8:  3294720,  79073280,  830269440,  4981616640,  18681062400,  44834549760,   67251824640,   57644421120,   21616657920;
  9: 24893440, 672122880, 8065474560, 56458321920, 254062448640, 762187345920, 1524374691840, 1959910318080, 1469932738560, 489977579520;
%F Formula
The row polynomials satisfy (n+n*x)*P(n,x) = (8*n-4+(32*n-16)*x+(24*n-12)*x^2)*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[((8*n - 4 + (32*n - 16)*x + (24*n - 12)*x^2)*P[n - 1, x])/(n + n*x)]];
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] = ((8*n - 4 + (32*n - 16)*x + (24*n - 12)*x^2)*v[i - 1])/(n + n*x)); 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.