Real-rooted atlas

A027467 → basis A013611 → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(20 + 12\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1201232
24004801441024
38000144008640172832768
4160000384000345600138240207361048576
532000009600000115200006912000207360024883233554432
6640000002304000003456000002764800001244160002985984029859841073741824
71280000000537600000096768000009676800000580608000020901888004180377603583180834359738368
8256000000001228800000002580480000003096576000002322432000001114767360003344302080057330892804299816961099511627776
951200000000027648000000006635520000000928972800000083607552000005016453120000200658124800051597803520077396705280515978035235184372088832
1010240000000000614400000000001658880000000002654208000000002786918400000002006581248000001003290624000003439853568000077396705280001031956070400619173642241125899906842624
1120480000000000013516800000000004055040000000000729907200000000087588864000000007357464576000000441447874560000018919194624000005675758387200001135151677440001362182012928074300837068836028797018963968
124096000000000000294912000000000009732096000000000019464192000000000026276659200000000025225592832000000017657914982400000090812134195200000340545503232000009081213419520000163461841551360017832200896512089161004482561152921504606846976
1381920000000000000638976000000000000230031360000000000050606899200000000007591034880000000000819831767040000000065586541363200000003935192481792000000177083661680640000059027887226880000014166692934451200023181861165465600231818611654656010699320537907236893488147419103232
14163840000000000000013762560000000000000536739840000000000001288175616000000000002125489766400000000002550587719680000000002295528947712000000001574076992716800000008263904211763200000033055616847052800000991668505411584000021636403754434560003245460563165184002995809750614016012839184645488641180591620717411303424
Technical details
Node id
n-25c780f7547ef542 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-b1029f17d1b64336

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:           20,            12;
  2:          400,           480,           144;
  3:         8000,         14400,          8640,          1728;
  4:       160000,        384000,        345600,        138240,         20736;
  5:      3200000,       9600000,      11520000,       6912000,       2073600,        248832;
  6:     64000000,     230400000,     345600000,     276480000,     124416000,      29859840,       2985984;
  7:   1280000000,    5376000000,    9676800000,    9676800000,    5806080000,    2090188800,     418037760,     35831808;
  8:  25600000000,  122880000000,  258048000000,  309657600000,  232243200000,  111476736000,   33443020800,   5733089280,   429981696;
  9: 512000000000, 2764800000000, 6635520000000, 9289728000000, 8360755200000, 5016453120000, 2006581248000, 515978035200, 77396705280, 5159780352;
%F Formula
The row polynomials satisfy P(n,x) = (20+12*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[(20 + 12*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] = (20 + 12*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.