A078812 → x ↦ x+1 → D
nonnegative coefficients
Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernelinterlacing (weak)
Recurrence
\(\left(-4 + 2\,n\right)\,P_{n}(x) = \left(3 + x + 3\,n + n x\right)\,P_{n-1}(x) + \left(5 + 6\,x + x^{2}\right)\,P_{n-1}'(x)\)
\(P_{1}(x) = 0\)
\(P_{2}(x) = 1\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | x9 | x10 | x11 | x12 | x13 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0 | ||||||||||||||
| 2 | 1 | 1 | |||||||||||||
| 3 | 6 | 2 | 8 | ||||||||||||
| 4 | 25 | 18 | 3 | 46 | |||||||||||
| 5 | 90 | 102 | 36 | 4 | 232 | ||||||||||
| 6 | 300 | 468 | 258 | 60 | 5 | 1091 | |||||||||
| 7 | 954 | 1902 | 1440 | 520 | 90 | 6 | 4912 | ||||||||
| 8 | 2939 | 7146 | 6915 | 3420 | 915 | 126 | 7 | 21468 | |||||||
| 9 | 8850 | 25414 | 30024 | 18960 | 6930 | 1470 | 168 | 8 | 91824 | ||||||
| 10 | 26195 | 86796 | 121278 | 93492 | 43575 | 12600 | 2212 | 216 | 9 | 386373 | |||||
| 11 | 76500 | 287364 | 464004 | 423220 | 240660 | 88620 | 21168 | 3168 | 270 | 10 | 1604984 | ||||
| 12 | 221016 | 928296 | 1701780 | 1794840 | 1207430 | 542052 | 164682 | 33480 | 4365 | 330 | 11 | 6598282 | |||
| 13 | 632916 | 2939556 | 6033780 | 7230340 | 5625180 | 2986452 | 1105272 | 285480 | 50490 | 5830 | 396 | 12 | 26895704 | ||
| 14 | 1799125 | 9156204 | 20808894 | 27941220 | 24706035 | 15167520 | 6635328 | 2086128 | 468270 | 73260 | 7590 | 468 | 13 | 108850055 | |
| 15 | 5082270 | 28127306 | 70127208 | 104338512 | 103419450 | 72163350 | 36496152 | 13556136 | 3701214 | 734250 | 102960 | 9672 | 546 | 14 | 437859040 |
Compute more
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Technical details
- Node id
n-47d961ccf2ecbd21· revision 0 · JSON- Definition source
derived:shift_x_plus_one- Fingerprint
f6-cb9ac7fd59880e43
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 -2)
- 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): no
Matches ?
No OEIS matches.
Submission text ?
Atlas rows n = 1, …, ascending powers of x
%e ExampleTriangle begins: 1: 0; 2: 1; 3: 6, 2; 4: 25, 18, 3; 5: 90, 102, 36, 4; 6: 300, 468, 258, 60, 5; 7: 954, 1902, 1440, 520, 90, 6; 8: 2939, 7146, 6915, 3420, 915, 126, 7; 9: 8850, 25414, 30024, 18960, 6930, 1470, 168, 8; 10: 26195, 86796, 121278, 93492, 43575, 12600, 2212, 216, 9;
%F FormulaThe row polynomials satisfy (2*n-4)*P(n,x) = (3*n+3+(n+1)*x)*P(n-1,x) + (5+6*x+x^2)*d/dx P(n-1,x) for n >= 3, with P(1,x) = 0, P(2,x) = 1.
%t MathematicaP[1, x_] := 0;
P[2, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((3*n + 3 + (n + 1)*x)*P[n - 1, x] + (5 + 6*x + x^2)*D[P[n - 1, x], x])/(2*n - 4)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten%o PARI/GPP(N) = {my(v = vector(N)); v[1] = 0; v[2] = 1; for(n = 3, N, my(i = n); v[i] = ((3*n + 3 + (n + 1)*x)*v[i - 1] + (5 + 6*x + x^2)*deriv(v[i - 1], x))/(2*n - 4)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)polytool c48629374597
Properties
- Real-rooted? Every row P_n, n ≥ 1, is zero or real-rooted with all roots in (−∞, -1]
- Coefficients of one sign? Every nonzero row, n ≥ 1: the coefficients of P_n have one sign
- Hadamard kernel (Malo)? Rows P_n, n ≥ 1, are Hadamard kernels (preserve real-rootedness)
- Real-rooted? Every row P_n, n ≥ 1, is zero or real-rooted with all roots in (−∞, 0]
- Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 2
Proof chains ? JSON
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Laguerre’s theorem on differential operators [SP14] polytool ? step ›
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from
basis_map_A007318 of Triangle read by rows: T(n, k) = binomial(n+k-1, 2*k-1).?
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Geometric basis map (elementary) polytool ? step ›
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from
basis_map_A007318 of Triangle read by rows: T(n, k) = binomial(n+k-1, 2*k-1).?
Related ?
Same fingerprint ?
References
- [Fav35] Jean Favard. Sur les polynômes de tchebicheff. C. R. Acad. Sci. Paris, 200:2052–2053, 1935.
- [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
- [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.
- [Sze39] G. Szegő. Orthogonal Polynomials. Colloquium publications, American Mathematical Society, 1939. doi:10.1090/coll/023