A038330 → basis A013609 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(8 + 16\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 64 + 256\,x + 256\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
064256256576
151230726144409613824
24096327689830413107265536331776
33276832768013107202621440262144010485767962624
426214431457281572864041943040629145605033164816777216191102976
5209715229360128176160768587202560117440512014092861449395240962684354564586471424
61677721626843545618790481927516192768187904819203006477107230064771072171798691844294967296110075314176
713421772824159191041932735283290194313216270582939648541165879296721554505728618475290624309237645312687194767362641807540224
Technical details
Node id
n-2272e70a10c82383 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-11aec07ce60b6d61

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:         64,          256,           256;
  1:        512,         3072,          6144,           4096;
  2:       4096,        32768,         98304,         131072,          65536;
  3:      32768,       327680,       1310720,        2621440,        2621440,         1048576;
  4:     262144,      3145728,      15728640,       41943040,       62914560,        50331648,        16777216;
  5:    2097152,     29360128,     176160768,      587202560,     1174405120,      1409286144,       939524096,       268435456;
  6:   16777216,    268435456,    1879048192,     7516192768,    18790481920,     30064771072,     30064771072,     17179869184,      4294967296;
  7:  134217728,   2415919104,   19327352832,    90194313216,   270582939648,    541165879296,    721554505728,    618475290624,    309237645312,     68719476736;
  8: 1073741824,  21474836480,  193273528320,  1030792151040,  3607772528640,   8658654068736,  14431090114560,  16492674416640,  12369505812480,   5497558138880,  1099511627776;
  9: 8589934592, 188978561024, 1889785610240, 11338713661440, 45354854645760, 126993593008128, 253987186016256, 362838837166080, 362838837166080, 241892558110720, 96757023244288, 17592186044416;
%F Formula
The row polynomials satisfy P(n,x) = (8+16*x)*P(n-1,x) for n >= 1, with P(0,x) = 64 + 256*x + 256*x^2.
%t Mathematica
P[0, x_] := 64 + 256*x + 256*x^2;
P[n_, x_] := P[n, x] = Expand[(8 + 16*x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 64 + 256*x + 256*x^2; for(n = 1, N, my(i = n + 1); v[i] = (8 + 16*x)*v[i - 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.