A123519 → basis A013611 → D
nonnegative coefficients
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernelinterlacing (weak)
Recurrence
\(\left(6 + 10\,n + 4\,n^{2}\right)\,P_{n}(x) = \left(42 + 96\,x + 38\,n + 80\,n x + 8\,n^{2} + 16\,n^{2} x\right)\,P_{n-1}(x) + \left(6 + 32\,x + 32\,x^{2} + 3\,n + 16\,n x + 16\,n x^{2}\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 56 + 128\,x\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 56 | 128 | 184 | |||||||
| 1 | 304 | 1408 | 1536 | 3248 | ||||||
| 2 | 1488 | 10368 | 23040 | 16384 | 51280 | |||||
| 3 | 6872 | 63872 | 215040 | 311296 | 163840 | 760920 | ||||
| 4 | 30568 | 355072 | 1603584 | 3522560 | 3768320 | 1572864 | 10852968 | |||
| 5 | 132448 | 1845504 | 10460160 | 30883840 | 50135040 | 42467328 | 14680064 | 150604384 | ||
| 6 | 562848 | 9146112 | 62383104 | 231587840 | 505610240 | 649592832 | 455081984 | 134217728 | 2048182688 | |
| 7 | 2356392 | 43744512 | 348825600 | 1560887296 | 4288184320 | 7409762304 | 7868514304 | 4697620480 | 1207959552 | 27427854760 |
Compute more
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Technical details
- Node id
n-8bfdefa57f60afcf· revision 0 · JSON- Definition source
derived:derivative- Fingerprint
f6-230a3cc4b5b885b4
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: 56, 128; 1: 304, 1408, 1536; 2: 1488, 10368, 23040, 16384; 3: 6872, 63872, 215040, 311296, 163840; 4: 30568, 355072, 1603584, 3522560, 3768320, 1572864; 5: 132448, 1845504, 10460160, 30883840, 50135040, 42467328, 14680064; 6: 562848, 9146112, 62383104, 231587840, 505610240, 649592832, 455081984, 134217728; 7: 2356392, 43744512, 348825600, 1560887296, 4288184320, 7409762304, 7868514304, 4697620480, 1207959552; 8: 9748888, 203534208, 1857853440, 9732767744, 32256000000, 70156025856, 100176756736, 90596966400, 47110422528, 10737418240; 9: 39946384, 926374528, 9524998656, 57187287040, 222063493120, 582871941120, 1047628087296, 1273592020992, 1002606428160, 461708984320, 94489280512;
%F FormulaThe row polynomials satisfy (4*n^2+10*n+6)*P(n,x) = (8*n^2+38*n+42+(16*n^2+80*n+96)*x)*P(n-1,x) + (3*n+6+(16*n+32)*x+(16*n+32)*x^2)*d/dx P(n-1,x) for n >= 1, with P(0,x) = 56 + 128*x.
%t MathematicaP[0, x_] := 56 + 128*x;
P[n_, x_] := P[n, x] = Expand[Together[((8*n^2 + 38*n + 42 + (16*n^2 + 80*n + 96)*x)*P[n - 1, x] + (3*n + 6 + (16*n + 32)*x + (16*n + 32)*x^2)*D[P[n - 1, x], x])/(4*n^2 + 10*n + 6)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten%o PARI/GPP(N) = {my(v = vector(N + 1)); v[1] = 56 + 128*x; for(n = 1, N, my(i = n + 1); v[i] = ((8*n^2 + 38*n + 42 + (16*n^2 + 80*n + 96)*x)*v[i - 1] + (3*n + 6 + (16*n + 32)*x + (16*n + 32)*x^2)*deriv(v[i - 1], x))/(4*n^2 + 10*n + 6)); 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_A013611 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_A013611 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