A178821 → basis A013610 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(-1 + n\right)\,P_{n}(x) = \left(8 + 12\,x + 2\,n + 3\,n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 0\)
\(P_{1}(x) = 15\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
11515
2180270450
31260378028357875
46720302404536022680105000
5302401814404082404082401530901181250
612096090720027216004082400306180091854011812500
74435203991680149688002993760033679800202078805051970108281250
81520640159667207185024017962560026943840024249456012124728025981560928125000
94942080593049603113510409340531201751349600210161952015762146406755205601266601057541015625
101537536020756736012454041604358914560980755776014711336640147113366409457287840354648294059108049058652343750
114612608069189120046702656001868106240049037788800882680198401103350248009457287840053197244100177324147002659862205439892578125
121341849602214051840166053888007472424960022417274880047076277248070614415872075658302720056743727040028371863520085115590560116066714403199218750000
133801907206843432960564583219202822916096009527341824002286562037760400148356608051447645849604823216798400321547786560014469650395203946268289604932835362022661132812500
141052835840205302988801847726899201016249794560381093672960010289529169920205790583398403086858750976034727160948480289393007904001736358047424071032829212801775820730320204902391960156884765625000
Technical details
Node id
n-f680a3b70a20ba67 · 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:      15;
  2:     180,      270;
  3:    1260,     3780,      2835;
  4:    6720,    30240,     45360,     22680;
  5:   30240,   181440,    408240,    408240,     153090;
  6:  120960,   907200,   2721600,   4082400,    3061800,     918540;
  7:  443520,  3991680,  14968800,  29937600,   33679800,   20207880,    5051970;
  8: 1520640, 15966720,  71850240, 179625600,  269438400,  242494560,  121247280,  25981560;
  9: 4942080, 59304960, 311351040, 934053120, 1751349600, 2101619520, 1576214640, 675520560, 126660105;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (2*n+8+(3*n+12)*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 15.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 15;
P[n_, x_] := P[n, x] = Expand[Together[((2*n + 8 + (3*n + 12)*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] = 15; for(n = 2, N, my(i = n + 1); v[i] = ((2*n + 8 + (3*n + 12)*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.