A038324 → Pₙ + Pₙ₊₁

nonnegative coefficients only rational roots

Proved for all n: all roots real what this means

Recurrence
\(P_{n}(x) = \left(11 + 10\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 12 + 10\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8Pn(1)
0121022
1132230100462
214523850340010009702
31597256870759004500010000203742
4175692785290140360012540005600001000004278582
51932612103951102329250027830000187000006700000100000089850222
62125873213367233036016860053905500048400000026070000078000000100000001886854662
7233846052168298295052985779009531291000107145500007707700000346500000089000000010000000039623947902

Computed in your browser ?

Technical details
Node id
n-82d14b372b8d9609 · revision 1 · JSON
Definition source
derived:obreschkoff_combination
Fingerprint
f6-3b70c6222436ef34

Observed on the stored rows ?

  • Degrees: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 (affine: slope 1, intercept 1)
  • 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 ?

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:          12,           10;
  1:         132,          230,           100;
  2:        1452,         3850,          3400,          1000;
  3:       15972,        56870,         75900,         45000,         10000;
  4:      175692,       785290,       1403600,       1254000,        560000,        100000;
  5:     1932612,     10395110,      23292500,      27830000,      18700000,       6700000,       1000000;
  6:    21258732,    133672330,     360168600,     539055000,     484000000,     260700000,      78000000,      10000000;
  7:   233846052,   1682982950,    5298577900,    9531291000,   10714550000,    7707700000,    3465000000,     890000000,    100000000;
  8:  2572306572,  20851272970,   75114186400,  157829980000,  213172960000,  191930200000,  115192000000,   44440000000,  10000000000,   1000000000;
  9: 28295372292, 255087068390, 1034768780100, 2487271644000, 3923202360000, 4242961800000, 3186414000000, 1640760000000, 554400000000, 111000000000, 10000000000;
%F Formula
The row polynomials satisfy P(n,x) = (11+10*x)*P(n-1,x) for n >= 1, with P(0,x) = 12 + 10*x.
%t Mathematica
P[0, x_] := 12 + 10*x;
P[n_, x_] := P[n, x] = Expand[(11 + 10*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] = 12 + 10*x; for(n = 1, N, my(i = n + 1); v[i] = (11 + 10*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, +inf)
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-4af761c482728828

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

No candidate equalities or related sequences.

References

  1. [Fis06] Steve Fisk. Polynomials, roots, and interlacing. arXiv:math/0612833. arXiv
  2. [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
  3. [Obr63] Nikola Obreschkoff. Verteilung und berechnung der nullstellen reeller polynome. Hochschulbücher für mathematik, VEB Deutscher Verlag der Wissenschaften, 1963.