A156992 → basis A013609 → basis A007318

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernelinterlacing (weak)

Recurrence

\(P_{n}(x) = \left(4 + 2\,x + 4\,n + 2\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
18412
2969624216
31536230411521925184
4307206144046080153601920155520
573728018432001843200921600230400230405598720
620643840619315207741440051609600193536003870720322560235146240
7660602880231211008034681651202890137600144506880043352064072253440516096011287019520
823781703680951268147201664719257601664719257601040449536004161798144010404495360148635648092897280609499054080
995126814720042807066624008561413324800998831554560074912366592003745618329600124853944320026754416640033443020800185794560036569943244800
1041855798476800209278992384000470877732864000627836977152000549357355008000329614413004800137339338752000392398110720007357464576000817496064000408748032002413616254156800
1120090783268864001104993079787520027624826994688000414372404920320004143724049203200029006068344422400145030341722112005179655061504000129491376537600021581896089600021581896089600980995276800173780370299289600
12104472072998092800626832437988556800172378920446853120028729820074475520003232104758378496000258568380670279680015083155539099648006464209516756992002020065473986560004489034386636800067335515799552006121410527232002550587719680013554868883344588800
13585043608789319680038027834571305779200114083503713917337600209153090142181785600261441362677727232000235297226409954508800156864817606636339200784324088033181696002941215330124431360081700425836789760001634008516735795200222819343191244800185682785992704007141645615104001138608986200945459200
14351026165273591808000245718315691514265600079858452599742136320001597169051994842726400021961074464929087488000219610744649290874880001647080584869681561600094118890563981803520004117701462174203904000137256715405806796800034314178851451699200062389416093548544000779867701169356800059989823166873600021424936845312000102474808758085091328000
Technical details
Node id
n-a0bec09b71e3cb85 · revision 0 · JSON
Definition source
derived:shift_x_plus_one
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:            8,             4;
  2:           96,            96,            24;
  3:         1536,          2304,          1152,           192;
  4:        30720,         61440,         46080,         15360,          1920;
  5:       737280,       1843200,       1843200,        921600,        230400,         23040;
  6:     20643840,      61931520,      77414400,      51609600,      19353600,       3870720,        322560;
  7:    660602880,    2312110080,    3468165120,    2890137600,    1445068800,     433520640,      72253440,      5160960;
  8:  23781703680,   95126814720,  166471925760,  166471925760,  104044953600,   41617981440,   10404495360,   1486356480,    92897280;
  9: 951268147200, 4280706662400, 8561413324800, 9988315545600, 7491236659200, 3745618329600, 1248539443200, 267544166400, 33443020800, 1857945600;
%F Formula
The row polynomials satisfy P(n,x) = (4*n+4+(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[(4*n + 4 + (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] = (4*n + 4 + (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.