A156992 → basis A007318 → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
16410
2547224150
364812968641923000
49720259202592011520192075000
5174960583200777600518400172800230402250000
6367416014696640244944002177280010886400290304032256078750000
7881798404115059208230118409144576006096384002438553605419008051609603150000000
8238085568012697896960296284262403950456832032920473600175575859205852528640111476736092897280141750000000
97142567040042855402240011428107264001777705574400177770557440011851370496005267275776001504935936002508226560018579456007087500000000
10235704712320015713647488000471409424640008380611993600097773806592000782190452736004345502515200016554295296000413857382400061312204800040874803200389812500000000
11848536964352006222604405248002074201468416000414840293683200055312039157760005162456988057600344163799203840016388752343040005462917447680001213981655040001618642206720098099527680023388750000000000
123309294160972800264743532877824009707262872186880021571695271526400032357542907289600034514712434442240026844776337899520015339872193085440063916134137856000189381138186240003787622763724800459105789542400255058771968001520268750000000000
131389903547608576001204583074594099200481833229837639680011778145618253414400196302426970890240002355629123650682880020938925543561625600139592836957077504006979641847853875200258505253624217600068934734299791360012533588054507520013926208949452800714164561510400106418812500000000000
146254565964238592000583759489995601920002529624456647608320006745665217726955520001236705289916608512000164894038655547801600016489403865554780160001256335532613697536000732862394024656896000325716619566514176000108572206522171392000263205349144657920004386755819077632000449923673751552000214249368453120007981410937500000000000
Technical details
Node id
n-511785ca0b4480e5 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-f06e51c139cfae05

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:           6,            4;
  2:          54,           72,            24;
  3:         648,         1296,           864,           192;
  4:        9720,        25920,         25920,         11520,          1920;
  5:      174960,       583200,        777600,        518400,        172800,         23040;
  6:     3674160,     14696640,      24494400,      21772800,      10886400,       2903040,       322560;
  7:    88179840,    411505920,     823011840,     914457600,     609638400,     243855360,     54190080,      5160960;
  8:  2380855680,  12697896960,   29628426240,   39504568320,   32920473600,   17557585920,   5852528640,   1114767360,    92897280;
  9: 71425670400, 428554022400, 1142810726400, 1777705574400, 1777705574400, 1185137049600, 526727577600, 150493593600, 25082265600, 1857945600;
%F Formula
The row polynomials satisfy P(n,x) = (3*n+3+(2*n+2)*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[(3*n + 3 + (2*n + 2)*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] = (3*n + 3 + (2*n + 2)*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.