A099097 → x ↦ x−12

OEIS matches ?

No 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.

Triangle begins:
   1:               1;
   2:             -36,              3;
   3:            1284,           -215,               9;
   4:          -45792,          11520,            -966,            27;
   5:         1633104,        -548232,           69013,         -3861,            81;
   6:       -58242240,       24451632,        -4106052,        344745,        -14472,         243;
   7:      2077123392,    -1046773584,       219796380,     -24613631,       1550394,      -52083,         729;
   8:    -74077535232,    43563557376,    -10979266176,    1537236864,    -129136668,     6508782,     -182250,      2187;
   9:   2641865787648, -1775882264832,    522259924320,  -87763165680,    9217412281,  -619550766,    26026515,   -624753,     6561;
  10: -94218237932544, 71260518673152, -23953689318528, 4696827628896, -592029462276, 49748822367, -2786911056, 100362159, -2108268, 19683;

The row polynomials satisfy P(n,x) = -(36-3*x)*P(n-1,x) - (12-x)*P(n-2,x) for n >= 3, with P(1,x) = 1, P(2,x) = -36 + 3*x.

P[1, x_] := 1;
P[2, x_] := -36 + 3*x;
P[n_, x_] := P[n, x] = Expand[-(36 - 3*x)*P[n - 1, x] - (12 - x)*P[n - 2, x]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten

P(N) = {my(v = vector(N)); v[1] = 1; v[2] = -36 + 3*x; for(n = 3, N, my(i = n); v[i] = -(36 - 3*x)*v[i - 1] - (12 - x)*v[i - 2]); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

Proved properties

• Real-rooted. Every row P_n, n >= 1, is zero or real-rooted with all roots in (104/9, 12]
  Every polynomial of the sequence has only real roots, inside the stated interval.
  by the cited steps: e-bc6cf8841f41c42f
• Coefficients of one sign. Every nonzero row, n >= 1: the coefficients of P_n(-x) 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-bc6cf8841f41c42f
• Interlacing of consecutive rows. Rows P_(m-1), P_m interlace (weak, unordered) for every m >= 2
  The roots of consecutive polynomials alternate on the real line.
  by the cited steps: e-bc6cf8841f41c42f

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

• preserver_image affine, shift 0 e-bc6cf8841f41c42f

  Affine, reversal and Möbius substitutions (elementary) polytool ?

  • premise (sequence): Riordan array (1, 3+x).
    uses: Every row P_n, n >= 1, is zero or real-rooted with all roots in (-4/9, 0]
    • theorem_check ma_wang_interval e-09c939a271fe525a root: theorem check

      Ma–Wang interval theorem [MW08, Thm 2, Cor 3] RealRooted RealRooted.affineEndpointStep_closed ?

Used in 1 proof step

• e-e4ffd1425a5524fc basis_map (A038327) → Riordan array (1, 3+x).

Related sequences ?

No candidate equalities or related sequences.

References

1. [MW08] Shi-Mei Ma and Yi Wang. q-Eulerian polynomials and polynomials with only real zeros. The Electronic Journal of Combinatorics, 15(1):Research Paper 17, January 2008. doi:10.37236/741