basis-map coefficients of A112227 → θ+1 → basis A013611

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + n\right)\,P_{n}(x) = \left(2 + 8\,x + n + 4\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 3 + 24\,x + 48\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
13244875
2448192256500
3580480128012803125
4612096038407680614418750
5716816808960268804300828672109375
6822426881792071680172032229376131072625000
79288403232256161280516096103219211796485898243515625
8103605760537603225601290240344064058982405898240262144019531250
Technical details
Node id
n-43d60147a8c06e7d · revision 0 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-03d7b8417365c509

Observed on the stored rows ?

  • Degrees: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (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:  3,  24,    48;
   2:  4,  48,   192,    256;
   3:  5,  80,   480,   1280,    1280;
   4:  6, 120,   960,   3840,    7680,    6144;
   5:  7, 168,  1680,   8960,   26880,   43008,    28672;
   6:  8, 224,  2688,  17920,   71680,  172032,   229376,   131072;
   7:  9, 288,  4032,  32256,  161280,  516096,  1032192,  1179648,    589824;
   8: 10, 360,  5760,  53760,  322560, 1290240,  3440640,  5898240,   5898240,   2621440;
   9: 11, 440,  7920,  84480,  591360, 2838528,  9461760, 21626880,  32440320,  28835840,  11534336;
  10: 12, 528, 10560, 126720, 1013760, 5677056, 22708224, 64880640, 129761280, 173015040, 138412032, 50331648;
%F Formula
The row polynomials satisfy (n+1)*P(n,x) = (n+2+(4*n+8)*x)*P(n-1,x) for n >= 2, with P(1,x) = 3 + 24*x + 48*x^2.
%t Mathematica
P[1, x_] := 3 + 24*x + 48*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((n + 2 + (4*n + 8)*x)*P[n - 1, x])/(n + 1)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 3 + 24*x + 48*x^2; for(n = 2, N, my(i = n); v[i] = ((n + 2 + (4*n + 8)*x)*v[i - 1])/(n + 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 ?

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.