basis-map coefficients of A113214, shifted → basis A013609 → D+1

only rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1-4-2-6
21216432
3-32-72-48-8-160
48025628812816768
5-192-800-1280-960-320-32-3584
644823044800512028807686416384
7-1024-6272-16128-22400-17920-8064-1792-128-73728
823041638450176860168960057344215044096256327680
9-5120-41472-147456-301056-387072-322560-172032-55296-9216-512-1441792
10112641024004147209830401505280154828810752004915201382402048010246291456
11-24576-247808-1126400-3041280-5406720-6623232-5677056-3379200-1351680-337920-45056-2048-27262976
12532485898242973696901120018247680259522562649292819464192101376003604480811008983044096117440512
13-114688-1384448-7667712-25772032-58572800-94887936-112459776-98402304-63258624-29286400-9371648-1916928-212992-8192-503316480
142457603211264193822727156531218040422432800768044281036844983910434440806419680460882001920238551044472832458752163842147483648
Technical details
Node id
n-e9f1e9290023f124 · revision 0 · JSON
Definition source
derived:one_plus_derivative
Fingerprint
f6-e99c3824c4864868

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:    -4,     -2;
  2:    12,     16,       4;
  3:   -32,    -72,     -48,      -8;
  4:    80,    256,     288,     128,      16;
  5:  -192,   -800,   -1280,    -960,    -320,     -32;
  6:   448,   2304,    4800,    5120,    2880,     768,      64;
  7: -1024,  -6272,  -16128,  -22400,  -17920,   -8064,   -1792,   -128;
  8:  2304,  16384,   50176,   86016,   89600,   57344,   21504,   4096,   256;
  9: -5120, -41472, -147456, -301056, -387072, -322560, -172032, -55296, -9216, -512;
%F Formula
The row polynomials satisfy (n+x)*P(n,x) = -(2*n+2+(2*n+4)*x+2*x^2)*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[(-(2*n + 2 + (2*n + 4)*x + 2*x^2)*P[n - 1, x])/(n + x)]];
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] = (-(2*n + 2 + (2*n + 4)*x + 2*x^2)*v[i - 1])/(n + x)); 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.