basis-map coefficients of A030528, shifted → θ+1 → basis A013609

only rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1-2-4-6
23121227
3-4-24-48-32-108
454012016080405
5-6-60-240-480-480-192-1458
67844201120168013444485103
7-8-112-672-2240-4480-5376-3584-1024-17496
89144100840321008016128161289216230459049
9-10-180-1440-6720-20160-40320-53760-46080-23040-5120-196830
101122019801056036960887041478401689601267205632011264649539
11-12-264-2640-15840-63360-177408-354816-506880-506880-337920-135168-24576-2125764
1213312343222880102960329472768768131788816473601464320878592319488532486908733
13-14-364-4368-32032-160160-576576-1537536-3075072-4612608-5125120-4100096-2236416-745472-114688-22320522
141542054604368024024096096028828806589440115315201537536015375360111820805591040172032024576071744535
Technical details
Node id
n-285ca2c8fd4bd5fc · revision 0 · JSON
Definition source
derived:basis_map_A013609
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 0)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • Nonnegative coefficients (nonn): no
  • 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:  -2,   -4;
  2:   3,   12,    12;
  3:  -4,  -24,   -48,   -32;
  4:   5,   40,   120,   160,     80;
  5:  -6,  -60,  -240,  -480,   -480,   -192;
  6:   7,   84,   420,  1120,   1680,   1344,    448;
  7:  -8, -112,  -672, -2240,  -4480,  -5376,  -3584,  -1024;
  8:   9,  144,  1008,  4032,  10080,  16128,  16128,   9216,   2304;
  9: -10, -180, -1440, -6720, -20160, -40320, -53760, -46080, -23040, -5120;
%F Formula
The row polynomials satisfy n*P(n,x) = -(n+1+(2*n+2)*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 + 1 + (2*n + 2)*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 + 1 + (2*n + 2)*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.