A136572 → (θ+1)² → basis A013611

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(1 + 4\,x + 2\,n + 8\,n x + n^{2} + 4\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
141620
218144288450
39611524608614412000
4600960057600153600153600375000
543208640069120027648005529600442368013500000
635280846720846720045158400135475200216760320144506880551250000
73225609031680108380160722534400289013760069363302409248440320528482304025200000000
Technical details
Node id
n-53d1470df2442b78 · revision 0 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-03d7b8417365c509

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:        4,         16;
  2:       18,        144,         288;
  3:       96,       1152,        4608,         6144;
  4:      600,       9600,       57600,       153600,        153600;
  5:     4320,      86400,      691200,      2764800,       5529600,       4423680;
  6:    35280,     846720,     8467200,     45158400,     135475200,     216760320,      144506880;
  7:   322560,    9031680,   108380160,    722534400,    2890137600,    6936330240,     9248440320,     5284823040;
  8:  3265920,  104509440,  1463132160,  11705057280,   58525286400,  187280916480,   374561832960,   428070666240,   214035333120;
  9: 36288000, 1306368000, 20901888000, 195084288000, 1170505728000, 4682022912000, 12485394432000, 21403533312000, 21403533312000, 9512681472000;
%F Formula
The row polynomials satisfy n*P(n,x) = (n^2+2*n+1+(4*n^2+8*n+4)*x)*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[((n^2 + 2*n + 1 + (4*n^2 + 8*n + 4)*x)*P[n - 1, x])/(n)]];
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] = ((n^2 + 2*n + 1 + (4*n^2 + 8*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 - 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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.