A136572 → D → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
111
24812
3187272162
49657611527682592
560048001440019200960048600
64320432001728003456003456001382401049760
7352804233602116800564480084672006773760225792025719120
83225604515840270950409031680018063360021676032014450688041287680705438720
93265920522547203657830401463132160365783040058525286405852528640334430208083607552021427701120
1036288000653184000522547200024385536000731566080001463132160001950842880001672151040008360755200018579456000714256704000
1143908480087816960007903526400042152140800014753249280003540779827200590129971200067443425280005058256896000224811417600044962283520025927518355200
12574801920012645642240012645642240007587385344000303495413760008497871585280016995743170560024279633100800024279633100800016186422067200064745688268800117719433216001018244357222400
13809512704001942830489600213711353856001424742359040006411340615680002051628997017600478713432637440082065159880704001025814498508800091183510978560005471010658713600198945842135040033157640355840043020824092646400
14122049607680031732897996800380794775961600279249502371840013962475118592000502649104269312001340397611384832002680795222769664004021192834154496004467992037949440003574393630359552001949669252923392006498897509744640099983038611456001945864966652006400
Technical details
Node id
n-46756cb125726a43 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (affine: slope 1, intercept -1)
  • 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:       0;
  1:       1;
  2:       4,        8;
  3:      18,       72,        72;
  4:      96,      576,      1152,        768;
  5:     600,     4800,     14400,      19200,       9600;
  6:    4320,    43200,    172800,     345600,     345600,     138240;
  7:   35280,   423360,   2116800,    5644800,    8467200,    6773760,    2257920;
  8:  322560,  4515840,  27095040,   90316800,  180633600,  216760320,  144506880,   41287680;
  9: 3265920, 52254720, 365783040, 1463132160, 3657830400, 5852528640, 5852528640, 3344302080, 836075520;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (n^2+2*n^2*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 1.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n^2 + 2*n^2*x)*P[n - 1, x])/(n - 1)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = 1; for(n = 2, N, my(i = n + 1); v[i] = ((n^2 + 2*n^2*x)*v[i - 1])/(n - 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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.