A134309 → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1123
228818
34244832108
4864192256128648
516160640128012805123888
6323841920512076806144204823328
7648965376179203584043008286728192139968
81282048143365734414336022937622937613107232768839808
92564608368641720325160961032192137625611796485898241310725038848
10512102409216049152017203204128768688128078643205898240262144052428830233088
11102422528225280135168054067201513881630277632432537604325376028835840115343362097152181398528
12204849152540672360448016220160519045121211105282076180482595225602306867201384120325033164883886081088391168
1340961064961277952937164846858240168689664449839104899678208134951731214994636801199570944654311424218103808335544326530347008
148192229376298188823855104131203072524812288157443686435987128326297747456839699660883969966086106906624305345331293952409613421772839182082048
Technical details
Node id
n-0df7e30176c773f9 · 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): 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:   1,    2;
  2:   2,    8,     8;
  3:   4,   24,    48,     32;
  4:   8,   64,   192,    256,    128;
  5:  16,  160,   640,   1280,   1280,     512;
  6:  32,  384,  1920,   5120,   7680,    6144,    2048;
  7:  64,  896,  5376,  17920,  35840,   43008,   28672,    8192;
  8: 128, 2048, 14336,  57344, 143360,  229376,  229376,  131072,  32768;
  9: 256, 4608, 36864, 172032, 516096, 1032192, 1376256, 1179648, 589824, 131072;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n-2+(4*n-4)*x)*P(n-1,x) for n >= 2, with P(0,x) = 1, P(1,x) = 1 + 2*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 1 + 2*x;
P[n_, x_] := P[n, x] = Expand[Together[((2*n - 2 + (4*n - 4)*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] = 1 + 2*x; for(n = 2, N, my(i = n + 1); v[i] = ((2*n - 2 + (4*n - 4)*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.