A038330 → basis A013611 → θ+1

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + 2\,x + n x\right)\,P_{n}(x) = \left(16 + 64\,x + 48\,x^{2} + 16\,n x + 16\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 256 + 1024\,x + 768\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
025610247682048
1409624576368641638481920
265536524288117964810485763276803145728
31048576104857603145728041943040262144006291456117440512
416777216201326592754974720134217728012582912006039797761174405124294967296
5268435456375809638416911433728375809638404697620480033822867456131533373442147483648154618822656
642949672966871947673636077725286496207267430415032385536001443109011456841813590016274877906944386547056645497558138880
7687194767361236950581248742170348748823089744183296432932703436805195192441241640407052320768197912092999685566277615616687194767360193514046488576
Technical details
Node id
n-13e35bca57344dde · revision 0 · JSON
Definition source
derived:theta_plus_one
Fingerprint
f6-e99c3824c4864868

Observed on the stored rows ?

  • Degrees: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (affine: slope 1, intercept 2)
  • 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:            256,            1024,              768;
  1:           4096,           24576,            36864,             16384;
  2:          65536,          524288,          1179648,           1048576,            327680;
  3:        1048576,        10485760,         31457280,          41943040,          26214400,           6291456;
  4:       16777216,       201326592,        754974720,        1342177280,        1258291200,         603979776,         117440512;
  5:      268435456,      3758096384,      16911433728,       37580963840,       46976204800,       33822867456,       13153337344,        2147483648;
  6:     4294967296,     68719476736,     360777252864,      962072674304,     1503238553600,     1443109011456,      841813590016,      274877906944,       38654705664;
  7:    68719476736,   1236950581248,    7421703487488,    23089744183296,    43293270343680,    51951924412416,    40407052320768,    19791209299968,     5566277615616,     687194767360;
  8:  1099511627776,  21990232555520,  148434069749760,   527765581332480,  1154487209164800,  1662461581197312,  1616282092830720,  1055531162664960,   445302209249280,  109951162777600,   12094627905536;
  9: 17592186044416, 387028092977152, 2902710697328640, 11610842789314560, 29027106973286400, 48765539715121152, 56893129667641344, 46443371157258240, 26124396275957760, 9675702324428800, 2128654511374336, 211106232532992;
%F Formula
The row polynomials satisfy (1+(n+2)*x)*P(n,x) = (16+(16*n+64)*x+(16*n+48)*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 256 + 1024*x + 768*x^2.
%t Mathematica
P[0, x_] := 256 + 1024*x + 768*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((16 + (16*n + 64)*x + (16*n + 48)*x^2)*P[n - 1, x])/(1 + (n + 2)*x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 256 + 1024*x + 768*x^2; for(n = 1, N, my(i = n + 1); v[i] = ((16 + (16*n + 64)*x + (16*n + 48)*x^2)*v[i - 1])/(1 + (n + 2)*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. [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.