A132200 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
18816
216321664
332969632256
464256384256641024
5128640128012806401284096
62561536384051203840153625616384
7512358410752179201792010752358451265536
810248192286725734471680573442867281921024262144
920481843273728172032258048258048172032737281843220481048576
1040964096018432049152086016010321928601604915201843204096040964194304
1181929011245056013516802703360378470437847042703360135168045056090112819216777216
12163841966081081344360448081100801297612815138816129761288110080360448010813441966081638467108864
1332768425984255590493716482342912042172416562298885622988842172416234291209371648255590442598432768268435456
14655369175045963776238551046560153613120307219680460822491955219680460813120307265601536238551045963776917504655361073741824
Technical details
Node id
n-084c295dbcbb83b2 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-77a7ed3b1d5f257e

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: yes
  • γ-positive (gamma_positive): yes
  • 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:    8,     8;
  2:   16,    32,    16;
  3:   32,    96,    96,     32;
  4:   64,   256,   384,    256,     64;
  5:  128,   640,  1280,   1280,    640,    128;
  6:  256,  1536,  3840,   5120,   3840,   1536,    256;
  7:  512,  3584, 10752,  17920,  17920,  10752,   3584,   512;
  8: 1024,  8192, 28672,  57344,  71680,  57344,  28672,  8192,  1024;
  9: 2048, 18432, 73728, 172032, 258048, 258048, 172032, 73728, 18432, 2048;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n-2+(2*n-2)*x)*P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 8 + 8*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 8 + 8*x;
P[n_, x_] := P[n, x] = Expand[Together[((2*n - 2 + (2*n - 2)*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] = 1; v[2] = 8 + 8*x; for(n = 2, N, my(i = n + 1); v[i] = ((2*n - 2 + (2*n - 2)*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. [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.