Real-rooted atlas

A013609 → basis A013610 → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(9 + 18\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
191827
281324324729
372943748748583219683
4656152488157464209952104976531441
559049590490236196047239204723920188956814348907
65314416377292318864608503056012754584010203667234012224387420489
7478296966961566401769396133923132026784626403214155168214277011261222003210460353203
8430467216887475364821232752192849310084821232752077139724032771397240324407984230411019960576282429536481
93874204896973568802557885504162603465686087810397058241562079411648208277254886417852336133128926168066561983592903687625597484987
1034867844016973568802062762119218033473130249601171559558736028117429409664468623823494405355700839936040167756299520178523361331203570467226624205891132094649
113138105960969038331139869038331139804142299868388016569199473552046393758525945692787517051891213255359578841601325535957884160883690638589440353476255435776642684100792325559060566555523
1228242953648167783088755447456139763098449707598420656022368419289295207157894172574464167017530693404162863157669029785635789470862872320318128629892198401908771779353190469409882885570561156831381426176150094635296999121
13254186582832966088511536554793062138438648581578901521675229078945076083760104684202273901536279157872730404096558315745460808192837473618191212288930526242434680320744420993947744256406047814880587776135349271626862592208229648656711684052555153018976267
142287679245496164055018873890883271524536058046661721962884643236639470795865537614655788318346215044396736495503864512100496834182945474561758694598201545804823449261309353944064234492613093539440641705400822498468659285270041124923432962623693573074567168374813367582081024109418989131512359209
Technical details
Node id
n-9f0b2634da8b3f8f · revision 0 · JSON
Definition source
derived:basis_map_A013610
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:         9,         18;
  2:        81,        324,         324;
  3:       729,       4374,        8748,         5832;
  4:      6561,      52488,      157464,       209952,       104976;
  5:     59049,     590490,     2361960,      4723920,      4723920,       1889568;
  6:    531441,    6377292,    31886460,     85030560,    127545840,     102036672,      34012224;
  7:   4782969,   66961566,   401769396,   1339231320,   2678462640,    3214155168,    2142770112,     612220032;
  8:  43046721,  688747536,  4821232752,  19284931008,  48212327520,   77139724032,   77139724032,   44079842304,  11019960576;
  9: 387420489, 6973568802, 55788550416, 260346568608, 781039705824, 1562079411648, 2082772548864, 1785233613312, 892616806656, 198359290368;
%F Formula
The row polynomials satisfy P(n,x) = (9+18*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[(9 + 18*x)*P[n - 1, 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] = (9 + 18*x)*v[i - 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. [ASW52] Michael Aissen, I. J. Schoenberg and A. M. Whitney. On the generating functions of totally positive sequences I. Journal d’Analyse Mathématique, 2(1):93–103, 1952. doi:10.1007/BF02786970
  2. [AW24] Christos A. Athanasiadis and David G. Wagner. Veronese sections and interlacing matrices of polynomials and formal power series. arXiv:2404.12989. arXiv
  3. [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
  4. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  5. [Edr53] Albert Edrei. Proof of a Conjecture of Schoenberg on the Generating Function of a Totally Positive Sequence. Canadian Journal of Mathematics, 5:86–94, 1953. doi:10.4153/CJM-1953-010-3
  6. [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
  7. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.