A178822 → basis A013611 → x ↦ x/(x+1)

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in [−1, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(n + n x\right)\,P_{n}(x) = \left(10 + 40\,x + 30\,x^{2} + 2\,n + 8\,n x + 6\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
1123648
2845047561344
34484032120961209628672
4201624192108864217728163296516096
580641209607257602177280326592019595528257536
629568532224399168015966720359251204311014421555072121110528
7101376212889619160064958003202874009605173217285173217282217093121660944384
Technical details
Node id
n-a0a241c9398f3361 · revision 0 · JSON
Definition source
derived:mobius_x_over_x_plus_one
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): yes
  • 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 = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:       1;
  1:      12,       36;
  2:      84,      504,       756;
  3:     448,     4032,     12096,      12096;
  4:    2016,    24192,    108864,     217728,      163296;
  5:    8064,   120960,    725760,    2177280,     3265920,     1959552;
  6:   29568,   532224,   3991680,   15966720,    35925120,    43110144,    21555072;
  7:  101376,  2128896,  19160064,   95800320,   287400960,   517321728,   517321728,   221709312;
  8:  329472,  7907328,  83026944,  498161664,  1868106240,  4483454976,  6725182464,  5764442112,  2161665792;
  9: 1025024, 27675648, 332107776, 2324754432, 10461394944, 31384184832, 62768369664, 80702189568, 60526642176, 20175547392;
%F Formula
The row polynomials satisfy (n+n*x)*P(n,x) = (2*n+10+(8*n+40)*x+(6*n+30)*x^2)*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[Together[((2*n + 10 + (8*n + 40)*x + (6*n + 30)*x^2)*P[n - 1, x])/(n + n*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 + 10 + (8*n + 40)*x + (6*n + 30)*x^2)*v[i - 1])/(n + n*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)

polytool c48629374597

Properties

Proof chains ? JSON

Same fingerprint ?

References

  1. [Bra06] Petter Brändén. On linear transformations preserving the Pólya frequency property. Transactions of the American Mathematical Society, 358(8):3697–3716, February 2006. doi:10.1090/s0002-9947-06-03856-6
  2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  3. [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
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.