A178820 → basis A007318 → reverse

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
14812
210404090
320120240160540
43528084011205602835
556560224044804480179213608
68410085040134402016016128537661236
71201680100803360067200806405376015360262440
816526401848073920184800295680295680168960422401082565
9220396031680147840443520887040118272010137605068801126404330260
102865720514802745609609602306304384384043929603294720146432029286416888014
113648008800804804801921920538137610762752153753601537536010250240410009674547264481508
12455109201201208008003603600115315202690688046126080576576005125120030750720111820801863680241805655
135601456017472012812806406400230630406150144012300288018450432020500480016400384089456640298188804587520892820880
14680190402475201980160108908804356352013069056029872128052276224069701632069701632050692096025346048077987840111411203252418920
Technical details
Node id
n-75aa1f320970e052 · revision 0 · JSON
Definition source
derived:reversal
Fingerprint
f6-11aec07ce60b6d61

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): 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:   1;
  1:   4,    8;
  2:  10,   40,    40;
  3:  20,  120,   240,    160;
  4:  35,  280,   840,   1120,    560;
  5:  56,  560,  2240,   4480,   4480,   1792;
  6:  84, 1008,  5040,  13440,  20160,  16128,    5376;
  7: 120, 1680, 10080,  33600,  67200,  80640,   53760,   15360;
  8: 165, 2640, 18480,  73920, 184800, 295680,  295680,  168960,  42240;
  9: 220, 3960, 31680, 147840, 443520, 887040, 1182720, 1013760, 506880, 112640;
%F Formula
The row polynomials satisfy n*P(n,x) = (n+3+(2*n+6)*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 + 3 + (2*n + 6)*x)*P[n - 1, x])/(n)]];
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 + 3 + (2*n + 6)*x)*v[i - 1])/(n)); 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

Candidate equalities ?

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.