A038284 → basis A007318

nonnegative coefficients only rational roots

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

Recurrence
\(P_{n}(x) = \left(14 + 6\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 196 + 168\,x + 36\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14x15x16Pn(1)
019616836400
12744352815122168000
2384166585642336120961296160000
353782411524809878404233609072077763200000
4752953619361664207446401185408038102406531844665664000000
51054135043162405124065949442904249601244678403200601645722882799361280000000
614757890565059848192758977228865055191043485099520119489126425604812831352832167961625600000000
72066104678479692609024136615901184136615901184878245079043763907481610754021376197522841621163161610077696512000000000
828925465497612396628070402390778270720273231802368020492385177601053894094848376390748160921773260801481421312014108774406046617610240000000000
9404956516966419090807228416409088726323205259712195584045083247390720270499484344321159283504332835488270540807604629401601086375628809311791104362797056204800000000000
10566939123752962915686922158086872690602229769818129431756809467481952051206491987624263683245993812131841192405890170883193944348672060837035212807821904527366094990540821767823364096000000000000
117937147732541444422125165273088113711789964165121786899556579737619145352391925760147692718451998728439583911542784361696453351833611625957429166082768085102182404745288746598455464413921283961743851521306069401681920000000000000
12111120068255580166667204095334809618572925694146969631839301189966233637524890688174489632164192018435276820676980583279820810127500693851340837978127601942528108508936005550082325191485833216362367504285696388250897448962559896027136783641640961638400000000000000
1315556809555781222410000806143002214403000241842900664320557187770824409088071638427677424025606754480323871408128482462880276529152026584689321359769601139343828058275840379781276019425280976580424049950721902429397499904027177562821427202687890828492801645647446016047018498457632768000000000000000
14217795333780937113614934537173549973504480038694864106291209600773897282125824013372506499785818112013754578114065412915210807168518194253004866166337866495426560319016271856317235201215300083262160896036459002497864826888522883700799569921521943517999923202006958485274624018431251395379201053214365450242821109907456655360000000000000000

Computed in your browser ?

Technical details
Node id
n-7288f584ad081a07 · revision 2 · JSON
Definition source
derived:basis_map_A007318
Fingerprint
f6-5184fe74b2189306

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 ?

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:           196,            168,             36;
  1:          2744,           3528,           1512,            216;
  2:         38416,          65856,          42336,          12096,           1296;
  3:        537824,        1152480,         987840,         423360,          90720,           7776;
  4:       7529536,       19361664,       20744640,       11854080,        3810240,         653184,          46656;
  5:     105413504,      316240512,      406594944,      290424960,      124467840,       32006016,        4572288,        279936;
  6:    1475789056,     5059848192,     7589772288,     6505519104,     3485099520,     1194891264,      256048128,      31352832,      1679616;
  7:   20661046784,    79692609024,   136615901184,   136615901184,    87824507904,    37639074816,    10754021376,    1975228416,    211631616,     10077696;
  8:  289254654976,  1239662807040,  2390778270720,  2732318023680,  2049238517760,  1053894094848,   376390748160,   92177326080,  14814213120,   1410877440,   60466176;
  9: 4049565169664, 19090807228416, 40908872632320, 52597121955840, 45083247390720, 27049948434432, 11592835043328, 3548827054080, 760462940160, 108637562880, 9311791104, 362797056;
%F Formula
The row polynomials satisfy P(n,x) = (14+6*x)*P(n-1,x) for n >= 1, with P(0,x) = 196 + 168*x + 36*x^2.
%t Mathematica
P[0, x_] := 196 + 168*x + 36*x^2;
P[n_, x_] := P[n, x] = Expand[(14 + 6*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] = 196 + 168*x + 36*x^2; for(n = 1, N, my(i = n + 1); v[i] = (14 + 6*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-37fb8ca4839f71ce, e-b35ead6daa50b714
  • 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-37fb8ca4839f71ce, e-b35ead6daa50b714
  • 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-37fb8ca4839f71ce, e-b35ead6daa50b714

Proof chains

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

Same fingerprint (2)

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