A038330 → basis A007318 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(4 + 16\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 16 + 128\,x + 256\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
016128256400
164768307240968000
22564096245766553665536160000
3102420480163840655360131072010485763200000
4409698304983040524288015728640251658241677721664000000
5163844587525505024367001601468006403523215364697620482684354561280000000
6655362097152293601282348810241174405120375809638475161927688589934592429496729625600000000
7262144943718415099494414092861448455716864338228674569019431321615461882265615461882265668719476736512000000000
Technical details
Node id
n-f7c069e2c825f8ee · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-03d7b8417365c509

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:      16,       128,        256;
  1:      64,       768,       3072,        4096;
  2:     256,      4096,      24576,       65536,        65536;
  3:    1024,     20480,     163840,      655360,      1310720,       1048576;
  4:    4096,     98304,     983040,     5242880,     15728640,      25165824,      16777216;
  5:   16384,    458752,    5505024,    36700160,    146800640,     352321536,     469762048,      268435456;
  6:   65536,   2097152,   29360128,   234881024,   1174405120,    3758096384,    7516192768,     8589934592,     4294967296;
  7:  262144,   9437184,  150994944,  1409286144,   8455716864,   33822867456,   90194313216,   154618822656,   154618822656,    68719476736;
  8: 1048576,  41943040,  754974720,  8053063680,  56371445760,  270582939648,  901943132160,  2061584302080,  3092376453120,  2748779069440,  1099511627776;
  9: 4194304, 184549376, 3690987520, 44291850240, 354334801920, 1984274890752, 7937099563008, 22677427322880, 45354854645760, 60473139527680, 48378511622144, 17592186044416;
%F Formula
The row polynomials satisfy P(n,x) = (4+16*x)*P(n-1,x) for n >= 1, with P(0,x) = 16 + 128*x + 256*x^2.
%t Mathematica
P[0, x_] := 16 + 128*x + 256*x^2;
P[n_, x_] := P[n, x] = Expand[(4 + 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] = 16 + 128*x + 256*x^2; for(n = 1, N, my(i = n + 1); v[i] = (4 + 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.