basis-map coefficients of A030528, shifted → basis A013610

only rational roots

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

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1-1-3-4
216916
3-1-9-27-27-64
41125410881256
5-1-15-90-270-405-243-1024
6118135540121514587294096
7-1-21-189-945-2835-5103-5103-2187-16384
812425215125670136082041217496656165536
9-1-27-324-2268-10206-30618-61236-78732-59049-19683-262144
1013040532401701061236153090262440295245196830590491048576
11-1-33-495-4455-26730-112266-336798-721710-1082565-1082565-649539-177147-4194304
121365945940400951924566735961732104324769543302603897234212576453144116777216
13-1-39-702-7722-57915-312741-1250964-3752892-8444007-14073345-16888014-13817466-6908733-1594323-67108864
14142819982881081486486218918775057841970268339405366591080496448150848361131223205224782969268435456

Generated b-files: A262710 (row sums) ?

Computed in your browser ?

Technical details
Node id
n-96b6c636cb527859 · revision 1 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-f9762973ec1089d7

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): no
  • 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: -1,  -3;
  2:  1,   6,    9;
  3: -1,  -9,  -27,   -27;
  4:  1,  12,   54,   108,     81;
  5: -1, -15,  -90,  -270,   -405,   -243;
  6:  1,  18,  135,   540,   1215,   1458,    729;
  7: -1, -21, -189,  -945,  -2835,  -5103,  -5103,  -2187;
  8:  1,  24,  252,  1512,   5670,  13608,  20412,  17496,   6561;
  9: -1, -27, -324, -2268, -10206, -30618, -61236, -78732, -59049, -19683;
%F Formula
The row polynomials satisfy P(n,x) = -(1+3*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[-(1 + 3*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] = -(1 + 3*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-226103a223be7e17
  • 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-226103a223be7e17
  • 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-226103a223be7e17

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 (16)

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