A156992 → basis A013609 → D+1

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(x + n\right)\,P_{n}(x) = \left(2 + 4\,x + 2\,x^{2} + 4\,n + 6\,n x + 2\,n x^{2} + 2\,n^{2} + 2\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7Pn(1)
011
18412
2729624192
3768172811521923840
49600307203456015360192092160
5138240576000921600691200230400230402580480
6225792011612160241920002580480014515200387072032256082575360
7412876802528870406502809609031680007225344003251404807225344051609602972712960
Technical details
Node id
n-22d41c489654ae69 · revision 0 · JSON
Definition source
derived:one_plus_derivative
Fingerprint
f6-e99c3824c4864868

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:           8,            4;
  2:          72,           96,           24;
  3:         768,         1728,         1152,           192;
  4:        9600,        30720,        34560,         15360,          1920;
  5:      138240,       576000,       921600,        691200,        230400,         23040;
  6:     2257920,     11612160,     24192000,      25804800,      14515200,       3870720,       322560;
  7:    41287680,    252887040,    650280960,     903168000,     722534400,     325140480,     72253440,      5160960;
  8:   836075520,   5945425920,  18207866880,   31213486080,   32514048000,   20808990720,   7803371520,   1486356480,    92897280;
  9: 18579456000, 150493593600, 535088332800, 1092472012800, 1404606873600, 1170505728000, 624269721600, 200658124800, 33443020800, 1857945600;
%F Formula
The row polynomials satisfy (n+x)*P(n,x) = (2*n^2+4*n+2+(2*n^2+6*n+4)*x+(2*n+2)*x^2)*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[((2*n^2 + 4*n + 2 + (2*n^2 + 6*n + 4)*x + (2*n + 2)*x^2)*P[n - 1, x])/(n + x)]];
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] = ((2*n^2 + 4*n + 2 + (2*n^2 + 6*n + 4)*x + (2*n + 2)*x^2)*v[i - 1])/(n + x)); 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.