A196347 → basis A013609 → basis A013609

palindromicγ-positivenonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(4\,n + 4\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1448
2326432128
3384115211523843072
46144245763686424576614498304
5122880614400122880012288006144001228803932160
6294912017694720442368005898240044236800176947202949120188743680
78257536057802752017340825602890137600289013760017340825605780275208257536010569646080
82642411520211392921607398752256014797504512018496880640014797504512073987522560211392921602642411520676457349120
995126814720856141332480342456532992079906524364801198597865472011985978654720799065243648034245653299208561413324809512681472048704929136640
103805072588800380507258880001712282664960004566087106560007990652436480009588782923776007990652436480004566087106560001712282664960003805072588800038050725888003896394330931200
111674231939072001841655132979200920827566489600027624826994688000552496539893760007734951558512640077349515585126400552496539893760002762482699468800092082756648960001841655132979200167423193907200342882701121945600
12803631330754560096435759690547200530396678298009600176798892766003200039779750872350720006364760139576115200742555349617213440063647601395761152003977975087235072000176798892766003200053039667829800960096435759690547200803631330754560032916739307706777600
134178882919923712005432547795900825600325952867754049536001195160515098181632002987901287745454080005378222317941817344007170963090589089792007170963090589089792005378222317941817344002987901287745454080001195160515098181632003259528677540495360054325477959008256004178882919923712003423340888001504870400
142340174435157278720032762442092201902080021295587359931236352008518234943972494540800234251460959243599872004685029219184871997440070275438287773079961600803147866145978056704007027543828777307996160046850292191848719974400234251460959243599872008518234943972494540800212955873599312363520032762442092201902080023401744351572787200383414179456168545484800
Technical details
Node id
n-1fa9c1ca735cbfa5 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-77a7ed3b1d5f257e

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: yes
  • γ-positive (gamma_positive): yes
  • 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,            4;
  2:          32,           64,            32;
  3:         384,         1152,          1152,           384;
  4:        6144,        24576,         36864,         24576,           6144;
  5:      122880,       614400,       1228800,       1228800,         614400,         122880;
  6:     2949120,     17694720,      44236800,      58982400,       44236800,       17694720,       2949120;
  7:    82575360,    578027520,    1734082560,    2890137600,     2890137600,     1734082560,     578027520,      82575360;
  8:  2642411520,  21139292160,   73987522560,  147975045120,   184968806400,   147975045120,   73987522560,   21139292160,   2642411520;
  9: 95126814720, 856141332480, 3424565329920, 7990652436480, 11985978654720, 11985978654720, 7990652436480, 3424565329920, 856141332480, 95126814720;
%F Formula
The row polynomials satisfy P(n,x) = (4*n+4*n*x)*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[(4*n + 4*n*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] = 1; for(n = 1, N, my(i = n + 1); v[i] = (4*n + 4*n*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.