A156992 → basis A013610 → D

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
166
272108180
3864259219445400
411520518407776038880180000
51728001036800233280023328008748006750000
629030402177280065318400979776007348320022044960283500000
754190080487710720182891520036578304004115059200246903552061725888013230000000
8111476736011705057280526727577601316818944001975228416001777705574408888527872019046845440680400000000
925082265600300987187200158018273280047405481984008888527872000106662334464007999675084800342843217920064283103360038272500000000
10613122048000827714764800049662885888000173820100608000391095226368000586642839552000586642839552000377127539712000141422827392000235704712320002338875000000000
11161864220672002427963310080001638875234304000655550093721600017208189960192000309747419283456003871842741043200033187223494656000186678132157440006222604405248000933390660787200154365750000000000
1245910578954240075752455274496005681434145587200025566453655142400076699360965427200016106865802739712002416029870410956800258860343258316800019414525744373760009707262872186880002912178861656064003971152993167360010945935000000000000
1313926208949452800250671761090150400206804202899374080010340210144968704000348982092392693760008375570217424650240014657247880493137920018845032989205463040017667218427380121600011778145618253414400053001655282140364800144549968951291904001806874611891148800830066737500000000000
14449923673751552000877351163815526400078961604743397376000434288826088685568000162858309783257088000043971743641479413760008794348728295882752000131915230924438241280001484046347899930214400012367052899166085120000742023173949965107200030355493479771299840007588873369942824960008756392349934028800067043851875000000000000
Technical details
Node id
n-09b0dafb5fde3569 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-f06e51c139cfae05

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:           6;
  2:          72,          108;
  3:         864,         2592,          1944;
  4:       11520,        51840,         77760,         38880;
  5:      172800,      1036800,       2332800,       2332800,        874800;
  6:     2903040,     21772800,      65318400,      97977600,      73483200,       22044960;
  7:    54190080,    487710720,    1828915200,    3657830400,    4115059200,     2469035520,     617258880;
  8:  1114767360,  11705057280,   52672757760,  131681894400,  197522841600,   177770557440,   88885278720,   19046845440;
  9: 25082265600, 300987187200, 1580182732800, 4740548198400, 8888527872000, 10666233446400, 7999675084800, 3428432179200, 642831033600;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n^2+2*n+(3*n^2+3*n)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 6.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 6;
P[n_, x_] := P[n, x] = Expand[Together[((2*n^2 + 2*n + (3*n^2 + 3*n)*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] = 6; for(n = 2, N, my(i = n + 1); v[i] = ((2*n^2 + 2*n + (3*n^2 + 3*n)*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. [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.