basis-map coefficients of A026729, shifted → basis A007318 → x ↦ x+1

only rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
2-2-1-3
34419
4-8-12-6-1-27
51632248181
6-32-80-80-40-10-1-243
76419224016060121729
8-128-448-672-560-280-84-14-1-2187
Technical details
Node id
n-0d4899845526eba3 · 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 -1)
  • 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

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:    1;
   2:   -2,    -1;
   3:    4,     4,     1;
   4:   -8,   -12,    -6,    -1;
   5:   16,    32,    24,     8,     1;
   6:  -32,   -80,   -80,   -40,   -10,    -1;
   7:   64,   192,   240,   160,    60,    12,    1;
   8: -128,  -448,  -672,  -560,  -280,   -84,  -14,   -1;
   9:  256,  1024,  1792,  1792,  1120,   448,  112,   16,   1;
  10: -512, -2304, -4608, -5376, -4032, -2016, -672, -144, -18, -1;
%F Formula
The row polynomials satisfy P(n,x) = -(2+x)*P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[-(2 + x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = -(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, v[i])))};
T(10)

polytool c48629374597

Properties

Proof chains ? JSON

Same fingerprint ?