A123519 → basis A013609 → D
nonnegative coefficients
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernelinterlacing (weak)
Recurrence
\(\left(3 + 5\,n + 2\,n^{2}\right)\,P_{n}(x) = \left(21 + 24\,x + 19\,n + 20\,n x + 4\,n^{2} + 4\,n^{2} x\right)\,P_{n-1}(x) + \left(6 + 16\,x + 8\,x^{2} + 3\,n + 8\,n x + 4\,n x^{2}\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 28 + 32\,x\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 28 | 32 | 60 | |||||||
| 1 | 152 | 352 | 192 | 696 | ||||||
| 2 | 744 | 2592 | 2880 | 1024 | 7240 | |||||
| 3 | 3436 | 15968 | 26880 | 19456 | 5120 | 70860 | ||||
| 4 | 15284 | 88768 | 200448 | 220160 | 117760 | 24576 | 666996 | |||
| 5 | 66224 | 461376 | 1307520 | 1930240 | 1566720 | 663552 | 114688 | 6110320 | ||
| 6 | 281424 | 2286528 | 7797888 | 14474240 | 15800320 | 10149888 | 3555328 | 524288 | 54869904 | |
| 7 | 1178196 | 10936128 | 43603200 | 97555456 | 134005760 | 115777536 | 61472768 | 18350080 | 2359296 | 485238420 |
Compute more
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Technical details
- Node id
n-63684c7cc5efa4d2· revision 0 · JSON- Definition source
derived:derivative- Fingerprint
f6-cda21f326eecd7ab
Observed on the stored rows ?
- Degrees: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 (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): no
Matches ?
No OEIS matches.
Submission text ?
Atlas rows n = 0, …, ascending powers of x
%e ExampleTriangle begins: 0: 28, 32; 1: 152, 352, 192; 2: 744, 2592, 2880, 1024; 3: 3436, 15968, 26880, 19456, 5120; 4: 15284, 88768, 200448, 220160, 117760, 24576; 5: 66224, 461376, 1307520, 1930240, 1566720, 663552, 114688; 6: 281424, 2286528, 7797888, 14474240, 15800320, 10149888, 3555328, 524288; 7: 1178196, 10936128, 43603200, 97555456, 134005760, 115777536, 61472768, 18350080, 2359296; 8: 4874444, 50883552, 232231680, 608297984, 1008000000, 1096187904, 782630912, 353894400, 92012544, 10485760; 9: 19973192, 231593632, 1190624832, 3574205440, 6939484160, 9107374080, 8184594432, 4974968832, 1958215680, 450887680, 46137344;
%F FormulaThe row polynomials satisfy (2*n^2+5*n+3)*P(n,x) = (4*n^2+19*n+21+(4*n^2+20*n+24)*x)*P(n-1,x) + (3*n+6+(8*n+16)*x+(4*n+8)*x^2)*d/dx P(n-1,x) for n >= 1, with P(0,x) = 28 + 32*x.
%t MathematicaP[0, x_] := 28 + 32*x;
P[n_, x_] := P[n, x] = Expand[Together[((4*n^2 + 19*n + 21 + (4*n^2 + 20*n + 24)*x)*P[n - 1, x] + (3*n + 6 + (8*n + 16)*x + (4*n + 8)*x^2)*D[P[n - 1, x], x])/(2*n^2 + 5*n + 3)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten%o PARI/GPP(N) = {my(v = vector(N + 1)); v[1] = 28 + 32*x; for(n = 1, N, my(i = n + 1); v[i] = ((4*n^2 + 19*n + 21 + (4*n^2 + 20*n + 24)*x)*v[i - 1] + (3*n + 6 + (8*n + 16)*x + (4*n + 8)*x^2)*deriv(v[i - 1], x))/(2*n^2 + 5*n + 3)); 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
- Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 1
Proof chains ? JSON
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Laguerre’s theorem on differential operators [SP14] polytool ? step ›
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from
basis_map_A013609 of Triangle read by rows: T(n,k) number of tilings of a 2n X 3 grid by dominoes, 2k of which are in a…?
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Geometric basis map (elementary) polytool ? step ›
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from
Triangle read by rows: T(n,k) number of tilings of a 2n X 3 grid by dominoes, 2k of which are in a vertical position (0…?
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Affine, reversal and Möbius substitutions (elementary) polytool ? step ›
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from
Triangle read by rows: T(n,k) number of tilings of a 2n X 3 grid by dominoes, 2k of which are in a vertical position (0…?
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Geometric basis map (elementary) polytool ? step ›
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from
basis_map_A013609 of Triangle read by rows: T(n,k) number of tilings of a 2n X 3 grid by dominoes, 2k of which are in a…?
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