A085880 → basis A013611 → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(-36 - 72\,x + 24\,n + 48\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
111
261218
372288288648
41080648012960864029160
5181441451524354565806082903041469664
632659232659201306368026127360261273601045094479361856
7615859273903104369515520985374720147806208011824496643941498884489613568
81200925441681295616100877736963362591232067251824640807021895685380145971215371845632262642393728
Technical details
Node id
n-50bfbc2b3dd01b9f · revision 0 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-11aec07ce60b6d61

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:           6,           12;
   3:          72,          288,           288;
   4:        1080,         6480,         12960,           8640;
   5:       18144,       145152,        435456,         580608,         290304;
   6:      326592,      3265920,      13063680,       26127360,       26127360,        10450944;
   7:     6158592,     73903104,     369515520,      985374720,     1478062080,      1182449664,       394149888;
   8:   120092544,   1681295616,   10087773696,    33625912320,    67251824640,     80702189568,     53801459712,     15371845632;
   9:  2401850880,  38429614080,  269007298560,  1076029194240,  2690072985600,   4304116776960,   4304116776960,   2459495301120,    614873825280;
  10: 48997757952, 881959643136, 7055677145088, 32926493343744, 98779480031232, 197558960062464, 263411946749952, 225781668642816, 112890834321408, 25086852071424;
%F Formula
The row polynomials satisfy n*P(n,x) = (24*n-36+(48*n-72)*x)*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[((24*n - 36 + (48*n - 72)*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] = 1; for(n = 2, N, my(i = n); v[i] = ((24*n - 36 + (48*n - 72)*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. [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.