A135838 → basis A013611

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, 0] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(P_{n}(x) = \left(8 + 32\,x + 32\,x^{2}\right)\,P_{n-2}(x)\)
\(P_{0}(x) = 1\)
\(P_{1}(x) = 4 + 8\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
14812
28323272
332192384256864
4645121536204810245184
52562560102402048020480819262208
6512614430720819201228809830432768373248
7204828672172032573440114688013762569175042621444478976
840966553645875218350084587520734003273400324194304104857626873856
91638429491223592961101004833030144660602888808038475497472377487368388608322486272
1032768655360589824031457280110100480264241152440401920503316480377487360167772160335544321934917632
1113107228835842883584017301504069206016019377684483875536896553648128055364812803690987520147639500826843545623219011584
1226214462914566920601646137344020761804806643777536155021475842657511014433218887680295279001601771674009664424509441073741824139314069504
13104857627262976327155712239914188811995709440431845539841151588106242303176212483454764318723838627020803070901616641675037245445583457484885899345921671768834048
1420971525872025676336332861069066243358798643213435194572840305583718492127048499216122233487362149631131648214963113164815633680957447816840478722405181685763435973836810030613004288

Computed in your browser ?

Technical details
Node id
n-8f0d536701873284 · revision 1 · JSON
Definition source
derived:basis_map_A013611
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

OEIS matches ?

No OEIS matches.

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:     1;
  1:     4,      8;
  2:     8,     32,      32;
  3:    32,    192,     384,      256;
  4:    64,    512,    1536,     2048,     1024;
  5:   256,   2560,   10240,    20480,    20480,     8192;
  6:   512,   6144,   30720,    81920,   122880,    98304,    32768;
  7:  2048,  28672,  172032,   573440,  1146880,  1376256,   917504,   262144;
  8:  4096,  65536,  458752,  1835008,  4587520,  7340032,  7340032,  4194304,  1048576;
  9: 16384, 294912, 2359296, 11010048, 33030144, 66060288, 88080384, 75497472, 37748736, 8388608;
%F Formula
The row polynomials satisfy P(n,x) = (8+32*x+32*x^2)*P(n-2,x) for n >= 2, with P(0,x) = 1, P(1,x) = 4 + 8*x.
%t Mathematica
P[0, x_] := 1;
P[1, x_] := 4 + 8*x;
P[n_, x_] := P[n, x] = Expand[(8 + 32*x + 32*x^2)*P[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] = 1; v[2] = 4 + 8*x; for(n = 2, N, my(i = n + 1); v[i] = (8 + 32*x + 32*x^2)*v[i - 2]); 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)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-0f9b3c3168d8e647
  • Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
    All coefficients of each polynomial have the same sign (after x -> -x when alternating).
    derived from the cited steps by a stated theorem: e-0f9b3c3168d8e647
  • Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-0f9b3c3168d8e647

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

Same fingerprint (67)

Equal up to content, sign, reversal and a small index shift.