basis-map coefficients of A030528, shifted → (θ+1)² → basis A013610

only rational roots

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

Recurrence

\(\left(n^{2}\right)\,P_{n}(x) = \left(-1 - 3\,x - 2\,n - 6\,n x - n^{2} - 3\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1-4-12-16
295481144
3-16-144-432-432-1024
4253001350270020256400
5-36-540-3240-9720-14580-8748-36864
649882661526460595357144235721200704
7-64-1344-12096-60480-181440-326592-326592-139968-1048576
8811944204121224724592701102248165337214171765314415308416
9-100-2700-32400-226800-1020600-3061800-6123600-7873200-5904900-1968300-26214400
1012136304900539204020582107409556185238903175524035724645238164307144929126877696
11-144-4752-71280-641520-3849120-16166304-48498912-103926240-155889360-155889360-93533616-25509168-603979776
1216960841003861003860677605532525064113837724292725576548860455731813940658632546359254116898135292835349504
13-196-7644-137592-1513512-11351340-61297236-245188944-735566832-1655025372-2758375620-3310050744-2708223336-1354111668-312487308-13153337344
1422594501842752211300182432251094593504925670751688801400443310367588662073501329931102514508339300108812544755022117450107616802560397977600
Technical details
Node id
n-5efe30144ac6947a · 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 0)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • Nonnegative coefficients (nonn): no
  • 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,   -12;
  2:    9,    54,     81;
  3:  -16,  -144,   -432,    -432;
  4:   25,   300,   1350,    2700,     2025;
  5:  -36,  -540,  -3240,   -9720,   -14580,    -8748;
  6:   49,   882,   6615,   26460,    59535,    71442,    35721;
  7:  -64, -1344, -12096,  -60480,  -181440,  -326592,  -326592,  -139968;
  8:   81,  1944,  20412,  122472,   459270,  1102248,  1653372,  1417176,   531441;
  9: -100, -2700, -32400, -226800, -1020600, -3061800, -6123600, -7873200, -5904900, -1968300;
%F Formula
The row polynomials satisfy n^2*P(n,x) = -(n^2+2*n+1+(3*n^2+6*n+3)*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[Together[(-(n^2 + 2*n + 1 + (3*n^2 + 6*n + 3)*x)*P[n - 1, x])/(n^2)]];
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] = (-(n^2 + 2*n + 1 + (3*n^2 + 6*n + 3)*x)*v[i - 1])/(n^2)); 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.