basis-map coefficients of A026729 → (θ+1)² → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 - 2\,n + n^{2}\right)\,P_{n}(x) = \left(n^{2} + 3\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
241216
395481144
4161444324321024
5253001350270020256400
6365403240972014580874836864
749882661526460595357144235721200704
864134412096604801814403265923265921399681048576
9811944204121224724592701102248165337214171765314415308416
1010027003240022680010206003061800612360078732005904900196830026214400
1112136304900539204020582107409556185238903175524035724645238164307144929126877696
12144475271280641520384912016166304484989121039262401558893601558893609353361625509168603979776
1316960841003861003860677605532525064113837724292725576548860455731813940658632546359254116898135292835349504
141967644137592151351211351340612972362451889447355668321655025372275837562033100507442708223336135411166831248730813153337344
1522594501842752211300182432251094593504925670751688801400443310367588662073501329931102514508339300108812544755022117450107616802560397977600
Technical details
Node id
n-f8b9bc0a520b731b · revision 0 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-f9762973ec1089d7

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 -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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:   1;
   2:   4,   12;
   3:   9,   54,    81;
   4:  16,  144,   432,    432;
   5:  25,  300,  1350,   2700,    2025;
   6:  36,  540,  3240,   9720,   14580,    8748;
   7:  49,  882,  6615,  26460,   59535,   71442,   35721;
   8:  64, 1344, 12096,  60480,  181440,  326592,  326592,  139968;
   9:  81, 1944, 20412, 122472,  459270, 1102248, 1653372, 1417176,  531441;
  10: 100, 2700, 32400, 226800, 1020600, 3061800, 6123600, 7873200, 5904900, 1968300;
%F Formula
The row polynomials satisfy (n^2-2*n+1)*P(n,x) = (n^2+3*n^2*x)*P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((n^2 + 3*n^2*x)*P[n - 1, x])/(n^2 - 2*n + 1)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = ((n^2 + 3*n^2*x)*v[i - 1])/(n^2 - 2*n + 1)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

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.