A196347 → basis A013611

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, 0] · coefficients of one sign · Hadamard kernel what this means

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1246
28323272
3482885763841296
43843072921612288614431104
5384038400153600307200307200122880933120
64608055296027648007372800110592008847360294912033592320
7645120903168054190080180633600361267200433520640289013760825753601410877440
8103219201651507201156055040462422016011560550400184968806401849688064010569646080264241152067722117120
9185794560334430208026754416640124853944320374561832960749123665920998831554560856141332480428070666240951268147203656994324480
1037158912007431782400066886041600035672555520001248539443200029964946636800499415777280005707608883200042807066624000190253629440003805072588800219419659468800
11817496064001798491340800179849134080001079094804480004316379217920001208586181017600241717236203520034531033743360003453103374336000230206891622400092082756648960016742319390720014481697524940800
12196199055360047087773286400517965506150400345310337433600015538965184512000497246885904384001160242733776896001988987543617536002486234429521920002209986159575040001325991695745024004821787984527360080363133075456001042682221795737600
135101175439360013263056142336001591566737080320011671489405255680058357447026278400021008680929460224005602314914522726400112046298290454528001680694474356817920018674383048409088000149395064387272704008148821693851238400271627389795041280041788829199237120081329213300067532800
14142832912302080039993215444582400519911800779571200415929440623656960022876119234301132800915044769372045312002745134308116135936006274592704265453568001098053723246454374400146407163099527249920014640716309952724992001064779367996561817600532389683998280908800163812210461009510400234017443515727872006831653917205672755200

Generated b-files: A047058 (row sums) ?

Computed in your browser ?

Technical details
Node id
n-ce701caf7dd0b8e7 · revision 1 · JSON
Definition source
derived:basis_map_A013611
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

OEIS matches ?

A generated b-file is computed from the node's definition along the row alignment of its OEIS link and starts at the entry's offset. It is an identification on a finite prefix, not a proof that the node and the OEIS entry agree for every n.

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:         1;
  1:         2,          4;
  2:         8,         32,          32;
  3:        48,        288,         576,          384;
  4:       384,       3072,        9216,        12288,         6144;
  5:      3840,      38400,      153600,       307200,       307200,       122880;
  6:     46080,     552960,     2764800,      7372800,     11059200,      8847360,      2949120;
  7:    645120,    9031680,    54190080,    180633600,    361267200,    433520640,    289013760,     82575360;
  8:  10321920,  165150720,  1156055040,   4624220160,  11560550400,  18496880640,  18496880640,  10569646080,   2642411520;
  9: 185794560, 3344302080, 26754416640, 124853944320, 374561832960, 749123665920, 998831554560, 856141332480, 428070666240, 95126814720;
%F Formula
The row polynomials satisfy P(n,x) = (2*n+4*n*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[(2*n + 4*n*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] = (2*n + 4*n*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)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-f21031c0731e2731
  • Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
    All coefficients of each polynomial have the same sign (after x -> -x when alternating).
    derived from the cited steps by a stated theorem: e-f21031c0731e2731
  • Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-f21031c0731e2731

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

Same fingerprint (67)

Equal up to content, sign, reversal and a small index shift.

References

  1. [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