A156992 → basis A013609 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(4 + 4\,x + 4\,n + 4\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
18816
29619296384
3153646084608153612288
43072012288018432012288030720491520
5737280368640073728007372800368640073728023592960
620643840123863040309657600412876800309657600123863040206438401321205760
7660602880462422016013872660480231211008002312110080013872660480462422016066060288084557168640
823781703680190253629440665887703040133177540608016647192576001331775406080665887703040190253629440237817036806088116142080
99512681472008561413324800342456532992007990652436480011985978654720011985978654720079906524364800342456532992008561413324800951268147200487049291366400
1041855798476800418557984768000188351093145600050226958172160008789717680128000105476612161536008789717680128000502269581721600018835109314560004185579847680004185579847680042860337640243200
112009078326886400220998615957504001104993079787520003314979239362560006629958478725120009281941870215168009281941870215168006629958478725120003314979239362560001104993079787520002209986159575040020090783268864004114592413463347200
12104472072998092800125366487597711360068951568178741248002298385605958041600051713676134055936000827418818144894976009653219545023774720082741881814489497600517136761340559360002298385605958041600068951568178741248001253664875977113600104472072998092800427917611000188108800
13585043608789319680076055669142611558400456334014855669350400167322472113745428480041830618028436357120007529511245118544281600100393483268247257088001003934832682472570880075295112451185442816004183061802843635712000167322472113745428480045633401485566935040076055669142611558400585043608789319680047926772432021068185600
143510261652735918080004914366313830285312000319433810398968545280001277735241595874181120003513771914388653998080007027543828777307996160001054131574316596199424000120472179921896708505600010541315743165961994240007027543828777307996160003513771914388653998080001277735241595874181120003194338103989685452800049143663138302853120003510261652735918080005751212691842528182272000
Technical details
Node id
n-5259916279b30fa5 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-77a7ed3b1d5f257e

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: yes
  • γ-positive (gamma_positive): yes
  • 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:            8,             8;
  2:           96,           192,             96;
  3:         1536,          4608,           4608,           1536;
  4:        30720,        122880,         184320,         122880,           30720;
  5:       737280,       3686400,        7372800,        7372800,         3686400,          737280;
  6:     20643840,     123863040,      309657600,      412876800,       309657600,       123863040,       20643840;
  7:    660602880,    4624220160,    13872660480,    23121100800,     23121100800,     13872660480,     4624220160,      660602880;
  8:  23781703680,  190253629440,   665887703040,  1331775406080,   1664719257600,   1331775406080,   665887703040,   190253629440,   23781703680;
  9: 951268147200, 8561413324800, 34245653299200, 79906524364800, 119859786547200, 119859786547200, 79906524364800, 34245653299200, 8561413324800, 951268147200;
%F Formula
The row polynomials satisfy P(n,x) = (4*n+4+(4*n+4)*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[(4*n + 4 + (4*n + 4)*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] = (4*n + 4 + (4*n + 4)*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. [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.