A156992 → basis A013611 → θ+1

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + 2\,n x\right)\,P_{n}(x) = \left(2 + 8\,x + 8\,x^{2} + 2\,n + 12\,n x + 16\,n x^{2} + 4\,n^{2} x + 8\,n^{2} x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
141620
224192288504
319223046912614415552
4192030720138240245760153600570240
523040460800276480073728009216000442368024261120
63225607741440580608002064384003870720003715891201445068801175731200
7516096014450688013005619205780275200144506880002080899072016184770560528482304063959777280
89289728029727129603121348608016647192576052022476800099883155456011653034803207610145177602140353331203860160675840
9185794560066886041600802632499200499415777280018728091648000449474199552006991820881920068491306598400385263599616009512681472000255989602713600
10408748032001634992128000220723937280001569592442880006866966937600001977686478028800384550148505600050226958172160004237899595776000209278992384000046041378324480018504391281868800
119809952768004316379217920064745688268800051796550615040002589827530752000087018205033267200203042478410956800331497923936256000372935164428288000276248269946880000121549238776627200241089399226368001448169752494080000
122550587719680012242821054464002020065473986560017956137546547200010100327369932800003878525710054195200105582088773697536002068547045362237440029088942825406464000287298200744755200001896168124915384320075219892558626816001358136948975206400121993819950101299200
1371416456151040037136557198540800668458029573734400653603406694318080040850212918394880000176472919807465881600549026861623227187200125491854085309071360021176750376895905792002614413626777272320000230068399156399964160013690020445670080512004943618494269751296008190610523050475520011006553533275806105600
14214249368453120001199796463337472000233960310350807040002495576643741941760001715708942572584960000823540292434840780800028823910235219427328000752951124511854428160001482372526382713405440002196107446492908748800002415718191142199623680001916602862393811271680001038159883796647772160003440056419681199718400052653924791038771200001058906357166879277056000
Technical details
Node id
n-feafafd9a91f4816 · revision 0 · JSON
Definition source
derived:theta_plus_one
Fingerprint
f6-7cabb77b45806852

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

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:          1;
  1:          4,          16;
  2:         24,         192,          288;
  3:        192,        2304,         6912,          6144;
  4:       1920,       30720,       138240,        245760,         153600;
  5:      23040,      460800,      2764800,       7372800,        9216000,        4423680;
  6:     322560,     7741440,     58060800,     206438400,      387072000,      371589120,      144506880;
  7:    5160960,   144506880,   1300561920,    5780275200,    14450688000,    20808990720,    16184770560,     5284823040;
  8:   92897280,  2972712960,  31213486080,  166471925760,   520224768000,   998831554560,  1165303480320,   761014517760,   214035333120;
  9: 1857945600, 66886041600, 802632499200, 4994157772800, 18728091648000, 44947419955200, 69918208819200, 68491306598400, 38526359961600, 9512681472000;
%F Formula
The row polynomials satisfy (1+2*n*x)*P(n,x) = (2*n+2+(4*n^2+12*n+8)*x+(8*n^2+16*n+8)*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((2*n + 2 + (4*n^2 + 12*n + 8)*x + (8*n^2 + 16*n + 8)*x^2)*P[n - 1, x])/(1 + 2*n*x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = ((2*n + 2 + (4*n^2 + 12*n + 8)*x + (8*n^2 + 16*n + 8)*x^2)*v[i - 1])/(1 + 2*n*x)); 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.