A121574 → x ↦ x+1 → D+1
nonnegative coefficients
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel
Recurrence
\(\left(17\,n + 11\,n x + 7\,n x^{3} + n x^{4} + n^{2} + 2\,n^{2} x + 8\,n^{2} x^{2} + n^{2} x^{3} - 3\,n^{3} + 3\,n^{3} x\right)\,P_{n}(x) = \left(3 + 49\,x + 102\,x^{2} + 70\,x^{3} + 15\,x^{4} + x^{5} + 106\,n + 98\,n x - 19\,n x^{2} - 26\,n x^{3} - 3\,n x^{4} - 25\,n^{2} - 56\,n^{2} x - 35\,n^{2} x^{2} - 4\,n^{2} x^{3} - 24\,n^{3} - 12\,n^{3} x\right)\,P_{n-1}(x) + \left(104 + 405\,x + 609\,x^{2} + 438\,x^{3} + 150\,x^{4} + 21\,x^{5} + x^{6} + 143\,n + 370\,n x + 341\,n x^{2} + 133\,n x^{3} + 20\,n x^{4} + n x^{5} + 39\,n^{2} + 69\,n^{2} x + 33\,n^{2} x^{2} + 3\,n^{2} x^{3}\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 1 | |||||||
| 1 | 4 | 1 | 5 | ||||||
| 2 | 17 | 9 | 1 | 27 | |||||
| 3 | 68 | 57 | 14 | 1 | 140 | ||||
| 4 | 264 | 307 | 121 | 19 | 1 | 712 | |||
| 5 | 1002 | 1500 | 828 | 209 | 24 | 1 | 3564 | ||
| 6 | 3739 | 6870 | 4917 | 1743 | 321 | 29 | 1 | 17620 | |
| 7 | 13768 | 30043 | 26538 | 12235 | 3164 | 457 | 34 | 1 | 86240 |
Compute more
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Technical details
- Node id
n-9c3fe92d57e53218· revision 0 · JSON- Definition source
derived:one_plus_derivative- Fingerprint
f6-8325caf9cc6f8183
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): no
Matches ?
No OEIS matches.
Submission text ?
Atlas rows n = 0, …, ascending powers of x
%e ExampleTriangle begins: 0: 1; 1: 4, 1; 2: 17, 9, 1; 3: 68, 57, 14, 1; 4: 264, 307, 121, 19, 1; 5: 1002, 1500, 828, 209, 24, 1; 6: 3739, 6870, 4917, 1743, 321, 29, 1; 7: 13768, 30043, 26538, 12235, 3164, 457, 34, 1; 8: 50159, 126897, 133705, 76301, 25686, 5203, 617, 39, 1; 9: 181142, 521691, 639548, 436477, 182118, 48014, 7972, 801, 44, 1;
%F FormulaThe row polynomials satisfy -(3*n^3-n^2-17*n-(3*n^3+2*n^2+11*n)*x-8*n^2*x^2-(n^2+7*n)*x^3-n*x^4)*P(n,x) = -(24*n^3+25*n^2-106*n-3+(12*n^3+56*n^2-98*n-49)*x+(35*n^2+19*n-102)*x^2+(4*n^2+26*n-70)*x^3+(3*n-15)*x^4-x^5)*P(n-1,x) + (39*n^2+143*n+104+(69*n^2+370*n+405)*x+(33*n^2+341*n+609)*x^2+(3*n^2+133*n+438)*x^3+(20*n+150)*x^4+(n+21)*x^5+x^6)*d/dx P(n-1,x) for n >= 1, with P(0,x) = 1.
%t MathematicaP[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[(-(24*n^3 + 25*n^2 - 106*n - 3 + (12*n^3 + 56*n^2 - 98*n - 49)*x + (35*n^2 + 19*n - 102)*x^2 + (4*n^2 + 26*n - 70)*x^3 + (3*n - 15)*x^4 - x^5)*P[n - 1, x] + (39*n^2 + 143*n + 104 + (69*n^2 + 370*n + 405)*x + (33*n^2 + 341*n + 609)*x^2 + (3*n^2 + 133*n + 438)*x^3 + (20*n + 150)*x^4 + (n + 21)*x^5 + x^6)*D[P[n - 1, x], x])/(-3*n^3 + n^2 + 17*n + (3*n^3 + 2*n^2 + 11*n)*x + 8*n^2*x^2 + (n^2 + 7*n)*x^3 + n*x^4)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten%o PARI/GPP(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = (-(24*n^3 + 25*n^2 - 106*n - 3 + (12*n^3 + 56*n^2 - 98*n - 49)*x + (35*n^2 + 19*n - 102)*x^2 + (4*n^2 + 26*n - 70)*x^3 + (3*n - 15)*x^4 - x^5)*v[i - 1] + (39*n^2 + 143*n + 104 + (69*n^2 + 370*n + 405)*x + (33*n^2 + 341*n + 609)*x^2 + (3*n^2 + 133*n + 438)*x^3 + (20*n + 150)*x^4 + (n + 21)*x^5 + x^6)*deriv(v[i - 1], x))/(-3*n^3 + n^2 + 17*n + (3*n^3 + 2*n^2 + 11*n)*x + 8*n^2*x^2 + (n^2 + 7*n)*x^3 + n*x^4)); 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
- Real-rooted? Every row P_n, n ≥ 0, is zero or real-rooted with all roots in (−∞, 0]
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Coefficients of one sign?
Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
derived from Laguerre’s theorem on differential operators
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Hadamard kernel (Malo)?
Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
derived from Laguerre’s theorem on differential operators
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 Riordan array (1/(1-2*x), x*(1+x)/(1-2*x)).?
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Geometric basis map (elementary) polytool ? step ›
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from
Riordan array (1/(1-2*x), x*(1+x)/(1-2*x)).?
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Liu–Wang theorem with a lag row [LW07, Thm 2.1] RealRooted ? step › direct check
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from
Riordan array (1/(1-2*x), x*(1+x)/(1-2*x)).?
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from
basis_map_A007318 of Riordan array (1/(1-2*x), x*(1+x)/(1-2*x)).?
References
- [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.