A120909 → basis A013610 → x ↦ x/(x+1)

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + x\right)\,P_{n}(x) = \left(3 + 12\,x + 9\,x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 3\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
033
192736
227162243432
381729218721875184
4243291613122262441968362208
57291093565610196830295245177147746496
621873936629524511809802657205318864615943238957952
765611377811240029620014518600435334807833348078314348907107495424
8196834723924960116297606961116026102678462644017693963443737681291401631289945088
9590491594323191318761339231326026540941807962282361592456446490458683486784401116226146715479341056
101771475314410717445355739562803013270470108477736922711943423046490458680523017660153486784401010460353203185752092672
115314411753755326306329523675696551420541793059662755306178988265918383546284110575319426165575319426165345191655699941431788272229025112064
1215943235739562894702786294702786206392438068530683702728810739295955082761533245592517787483548569038331139806213449802582338915443777284728860944326748301344768
134782969186535791335764423836934086618277005649635149583050802959833220321161794996609634840387423716783673123728613058077484743356666088511536554330442557682777625597484987320979616137216
1414348907602654094117517548331410210579961163423728467698054237080231412440668609107699796578088282711966017481565423932034962848135898052443925239161511756693929371133817320275094369454686303773648833851755393646592
Technical details
Node id
n-953c608d8b7bae18 · 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:     3;
  1:     9,      27;
  2:    27,     162,      243;
  3:    81,     729,     2187,      2187;
  4:   243,    2916,    13122,     26244,     19683;
  5:   729,   10935,    65610,    196830,    295245,     177147;
  6:  2187,   39366,   295245,   1180980,   2657205,    3188646,    1594323;
  7:  6561,  137781,  1240029,   6200145,  18600435,   33480783,   33480783,   14348907;
  8: 19683,  472392,  4960116,  29760696, 111602610,  267846264,  401769396,  344373768,  129140163;
  9: 59049, 1594323, 19131876, 133923132, 602654094, 1807962282, 3615924564, 4649045868, 3486784401, 1162261467;
%F Formula
The row polynomials satisfy (1+x)*P(n,x) = (3+12*x+9*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 3.
%t Mathematica
P[0, x_] := 3;
P[n_, x_] := P[n, x] = Expand[Together[((3 + 12*x + 9*x^2)*P[n - 1, x])/(1 + x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 3; for(n = 1, N, my(i = n + 1); v[i] = ((3 + 12*x + 9*x^2)*v[i - 1])/(1 + 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.