basis-map coefficients of A026729 → basis A007318 → D+1

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernelinterlacing (weak)

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2213
33418
4496120
5516188148
66254030101112
7736758045121256
884912617514063141576
9964196336350224841611280
1010812885887566303361081812816
11111004059601470151210504801352016144
12121215501485264032342772165066016522113312
131314472622004455633664684752247588019824128672
14141699363146715011583137281201277223575114423426161440
15151961183436811011200202702727456210211201250051456273281131072
Technical details
Node id
n-74bbcae8a0010b72 · revision 0 · JSON
Definition source
derived:one_plus_derivative
Fingerprint
f6-e99c3824c4864868

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): 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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:  1;
   2:  2,  1;
   3:  3,  4,   1;
   4:  4,  9,   6,   1;
   5:  5, 16,  18,   8,   1;
   6:  6, 25,  40,  30,  10,   1;
   7:  7, 36,  75,  80,  45,  12,   1;
   8:  8, 49, 126, 175, 140,  63,  14,   1;
   9:  9, 64, 196, 336, 350, 224,  84,  16,  1;
  10: 10, 81, 288, 588, 756, 630, 336, 108, 18, 1;
%F Formula
The row polynomials satisfy (n-1+x)*P(n,x) = (n+(n+1)*x+x^2)*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[Together[((n + (n + 1)*x + x^2)*P[n - 1, x])/(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] = ((n + (n + 1)*x + x^2)*v[i - 1])/(n - 1 + x)); 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 ?

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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.