A038338 → 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
\(P_{n}(x) = \left(24 + 48\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 576 + 2304\,x + 2304\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
0576230423045184
11382482944165888110592373248
23317762654208796262410616832530841626873856
37962624796262403185049606370099206370099202548039681934917632
419110297622932357121146617856030576476160458647142403669177139212230590464139314069504
5458647142464210599936385263599616128421199872025684239974403082108796928205473919795258706834227210030613004288
61100753141761761205026816123284351877124931374075084812328435187712019725496300339219725496300339211271712171622428179280429056722204136308736
7264180754022447552535724032380420285792256177529466703052853258840010915841065176800218316814202357336244224121734491453521926086724572676096135260546059468851998697814228992

Computed in your browser ?

Technical details
Node id
n-c201d29a62400440 · revision 1 · JSON
Definition source
derived:basis_map_A013611
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

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:              576,              2304,               2304;
  1:            13824,             82944,             165888,              110592;
  2:           331776,           2654208,            7962624,            10616832,             5308416;
  3:          7962624,          79626240,          318504960,           637009920,           637009920,            254803968;
  4:        191102976,        2293235712,        11466178560,         30576476160,         45864714240,          36691771392,          12230590464;
  5:       4586471424,       64210599936,       385263599616,       1284211998720,       2568423997440,        3082108796928,        2054739197952,         587068342272;
  6:     110075314176,     1761205026816,     12328435187712,      49313740750848,     123284351877120,      197254963003392,      197254963003392,      112717121716224,       28179280429056;
  7:    2641807540224,    47552535724032,    380420285792256,    1775294667030528,    5325884001091584,    10651768002183168,    14202357336244224,    12173449145352192,     6086724572676096,     1352605460594688;
  8:   63403380965376,  1268067619307520,  11412608573767680,   60867245726760960,  213035360043663360,   511284864104792064,   852141440174653440,   973875931628175360,   730406948721131520,   324625310542725120,    64925062108545024;
  9: 1521681143169024, 33476985149718528, 334769851497185280, 2008619108983111680, 8034476435932446720, 22496534020610850816, 44993068041221701632, 64275811487459573760, 64275811487459573760, 42850540991639715840, 17140216396655886336, 3116402981210161152;
%F Formula
The row polynomials satisfy P(n,x) = (24+48*x)*P(n-1,x) for n >= 1, with P(0,x) = 576 + 2304*x + 2304*x^2.
%t Mathematica
P[0, x_] := 576 + 2304*x + 2304*x^2;
P[n_, x_] := P[n, x] = Expand[(24 + 48*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] = 576 + 2304*x + 2304*x^2; for(n = 1, N, my(i = n + 1); v[i] = (24 + 48*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)

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-c462762e7768ae01
  • 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-c462762e7768ae01
  • 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-c462762e7768ae01

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.

References

  1. [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