basis-map coefficients of A112227 → basis A013611 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(1 + 4\,x + n + 4\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 8 + 32\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8Pn(1)
183240
21296192300
31619276810242000
42032019205120512012500
524480384015360307202457675000
628672672035840107520172032114688437500
73289610752716802867206881289175045242882500000
836115216128129024645120206438441287684718592235929614062500
Technical details
Node id
n-fdcf3b7c800e805f · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-03d7b8417365c509

Observed on the stored rows ?

  • Degrees: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 (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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:  8,   32;
   2: 12,   96,   192;
   3: 16,  192,   768,   1024;
   4: 20,  320,  1920,   5120,    5120;
   5: 24,  480,  3840,  15360,   30720,    24576;
   6: 28,  672,  6720,  35840,  107520,   172032,   114688;
   7: 32,  896, 10752,  71680,  286720,   688128,   917504,   524288;
   8: 36, 1152, 16128, 129024,  645120,  2064384,  4128768,  4718592,   2359296;
   9: 40, 1440, 23040, 215040, 1290240,  5160960, 13762560, 23592960,  23592960,  10485760;
  10: 44, 1760, 31680, 337920, 2365440, 11354112, 37847040, 86507520, 129761280, 115343360, 46137344;
%F Formula
The row polynomials satisfy n*P(n,x) = (n+1+(4*n+4)*x)*P(n-1,x) for n >= 2, with P(1,x) = 8 + 32*x.
%t Mathematica
P[1, x_] := 8 + 32*x;
P[n_, x_] := P[n, x] = Expand[Together[((n + 1 + (4*n + 4)*x)*P[n - 1, x])/(n)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 8 + 32*x; for(n = 2, N, my(i = n); v[i] = ((n + 1 + (4*n + 4)*x)*v[i - 1])/(n)); 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.