A008278 → x ↦ x+1 (shift +1) → x ↦ x+1

nonnegative coefficients

Proved for all n: all roots real, in (−∞, −1] · coefficients of one sign · Hadamard kernel what this means

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1314
2117119
34946131109
4257322139231742
51539242714293784115815
6102991964514744543899175151193
775905170236155822741781926125741411498118
86094411573732170391499764633867165938670727115296321
952844511545963719361158134921845683129146644922262917650529160987817
1049134923160769075228925579185388856935319533022212761701587500384709510431754940848
114870269291763691946281690816326030963791533391979597306260154161540255935602538749127686206919983845261
12512090544120346588710360508936293747506289325282270022115537901723618685680766948592105599861866769035197941191140329768789
13568780920672461361620314794252887555541694529624217797957322215685050828181181784021184655616376165540743591093529913797985866821712087182244308
14664920021819311429502967366176677347148425507433702714763122545842484308748981810005277690555306225312121314829431183220040171807124804104472782280142316411132725315072135

Computed in your browser ?

Technical details
Node id
n-1639e69c5d7e0691 · revision 1 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-75d63132b26da3ac

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): 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.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:       1;
  1:       3,        1;
  2:      11,        7,        1;
  3:      49,       46,       13,        1;
  4:     257,      322,      139,       23,       1;
  5:    1539,     2427,     1429,      378,      41,       1;
  6:   10299,    19645,    14744,     5438,     991,      75,      1;
  7:   75905,   170236,   155822,    74178,   19261,    2574,    141,     1;
  8:  609441,  1573732,  1703914,   997646,  338671,   65938,   6707,   271,   1;
  9: 5284451, 15459637, 19361158, 13492184, 5683129, 1466449, 222629, 17650, 529, 1;
%F Formula
The row polynomials satisfy P(n,x) = (2*n+1+n*x)*P(n-1,x) - (4+4*x+x^2)*d/dx 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 + 1 + n*x)*P[n - 1, x] - (4 + 4*x + x^2)*D[P[n - 1, x], 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 + 1 + n*x)*v[i - 1] - (4 + 4*x + x^2)*deriv(v[i - 1], x)); 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, -1]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-8abcc7766de04335
  • 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-8abcc7766de04335
  • 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-8abcc7766de04335

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. [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
  2. [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