A178822 → basis A013610 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(10 + 15\,x + 2\,n + 3\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 18\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
11818
2252378630
320166048453612600
412096544328164840824189000
5604803628808164808164803061802362500
62661121995840598752089812806735960202078825987500
7106444895800323592512071850240808315204849891212124728259875000
8395366441513472186810624467026560700539840630485856315242928675520562413125000
9138378241660538888717829122615348736490377888058845346564413400992189145756835464829421114843750
104612608062270208037362124801307674368029422673280441340099204413400992028371863520106394488201773241470175957031250
11147603456221405184014944849920597793996801569209241602824576634883530720793603026332108801702311811205674372704085115590561407656250000
1245622886475277762565645832192025406244864076218734592016005934264322400890139648257238229248019292867193609646433596802893930079043946268289610877343750000
13136868659224636358656203249958912101624979456034298430566408231623335936144053408378881852115250585617363580474240115757203161605209074142272142065658425617758207303281580078125000
14400077619278015135744702136221696386174921932814481559572480391002108456967820042169139211730063253708813196321160422410996934300352065981605802112269924751008646748118775216778629089448596162109375000
Technical details
Node id
n-819b1fbbf31fdfda · 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:       18;
  2:      252,       378;
  3:     2016,      6048,      4536;
  4:    12096,     54432,     81648,      40824;
  5:    60480,    362880,    816480,     816480,     306180;
  6:   266112,   1995840,   5987520,    8981280,    6735960,    2020788;
  7:  1064448,   9580032,  35925120,   71850240,   80831520,   48498912,   12124728;
  8:  3953664,  41513472, 186810624,  467026560,  700539840,  630485856,  315242928,   67552056;
  9: 13837824, 166053888, 871782912, 2615348736, 4903778880, 5884534656, 4413400992, 1891457568, 354648294;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n+10+(3*n+15)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 18.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 18;
P[n_, x_] := P[n, x] = Expand[Together[((2*n + 10 + (3*n + 15)*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] = 18; for(n = 2, N, my(i = n + 1); v[i] = ((2*n + 10 + (3*n + 15)*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.