basis-map coefficients of A113214, shifted → D → basis A013611

only rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
1-1-1
24812
3-12-48-48-108
432192384256864
5-80-640-1920-2560-1280-6480
6192192076801536015360614446656
7-448-5376-26880-71680-107520-86016-28672-326592
8102414336860162867205734406881284587521310722239488
9-2304-36864-258048-1032192-2580480-4128768-4128768-2359296-589824-15116544
10512092160737280344064010321920206438402752512023592960117964802621440100776960
11-11264-225280-2027520-10813440-37847040-90832896-151388160-173015040-129761280-57671680-11534336-665127936
122457654067254067203244032012976128036333158472666316810380902401038090240692060160276824064503316484353564672
13-53248-1277952-14057472-93716480-421724160-1349517312-3148873728-5398069248-6747586560-5997854720-3598712832-1308622848-218103808-28298170368
14114688298188835782656262406144131203072047233105921259549491225190989824377864847364198498304033587986432183207198726106906624939524096182849716224
Technical details
Node id
n-73f1b843be1a1e11 · revision 0 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (affine: slope 1, intercept -1)
  • 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:     0;
  1:    -1;
  2:     4,      8;
  3:   -12,    -48,     -48;
  4:    32,    192,     384,      256;
  5:   -80,   -640,   -1920,    -2560,    -1280;
  6:   192,   1920,    7680,    15360,    15360,     6144;
  7:  -448,  -5376,  -26880,   -71680,  -107520,   -86016,   -28672;
  8:  1024,  14336,   86016,   286720,   573440,   688128,   458752,   131072;
  9: -2304, -36864, -258048, -1032192, -2580480, -4128768, -4128768, -2359296, -589824;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = -(2*n+4*n*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = -1.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := -1;
P[n_, x_] := P[n, x] = Expand[Together[(-(2*n + 4*n*x)*P[n - 1, x])/(n - 1)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = -1; for(n = 2, N, my(i = n + 1); v[i] = (-(2*n + 4*n*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 - 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.