basis-map coefficients of A030528, shifted → (θ+1)² → basis A013611
only rational roots
Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernelinterlacing (weak)
Recurrence
\(\left(n^{2}\right)\,P_{n}(x) = \left(-1 - 4\,x - 2\,n - 8\,n x - n^{2} - 4\,n^{2} x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 1 | |||||||
| 1 | -4 | -16 | -20 | ||||||
| 2 | 9 | 72 | 144 | 225 | |||||
| 3 | -16 | -192 | -768 | -1024 | -2000 | ||||
| 4 | 25 | 400 | 2400 | 6400 | 6400 | 15625 | |||
| 5 | -36 | -720 | -5760 | -23040 | -46080 | -36864 | -112500 | ||
| 6 | 49 | 1176 | 11760 | 62720 | 188160 | 301056 | 200704 | 765625 | |
| 7 | -64 | -1792 | -21504 | -143360 | -573440 | -1376256 | -1835008 | -1048576 | -5000000 |
Compute more
?
Technical details
- Node id
n-41592f90ceca7e00· revision 0 · JSON- Definition source
derived:basis_map_A013611- Fingerprint
f6-03d7b8417365c509
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): no - 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 ExampleTriangle begins: 0: 1; 1: -4, -16; 2: 9, 72, 144; 3: -16, -192, -768, -1024; 4: 25, 400, 2400, 6400, 6400; 5: -36, -720, -5760, -23040, -46080, -36864; 6: 49, 1176, 11760, 62720, 188160, 301056, 200704; 7: -64, -1792, -21504, -143360, -573440, -1376256, -1835008, -1048576; 8: 81, 2592, 36288, 290304, 1451520, 4644864, 9289728, 10616832, 5308416; 9: -100, -3600, -57600, -537600, -3225600, -12902400, -34406400, -58982400, -58982400, -26214400;
%F FormulaThe row polynomials satisfy n^2*P(n,x) = -(n^2+2*n+1+(4*n^2+8*n+4)*x)*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[(-(n^2 + 2*n + 1 + (4*n^2 + 8*n + 4)*x)*P[n - 1, x])/(n^2)]];
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] = (-(n^2 + 2*n + 1 + (4*n^2 + 8*n + 4)*x)*v[i - 1])/(n^2)); 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 Geometric basis map (elementary)
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Hadamard kernel (Malo)?
Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
derived from Geometric basis map (elementary)
- Interlacing of consecutive rows? Rows P_(m-1), P_m interlace (weak, unordered) for every m ≥ 1
Proof chains ? JSON
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Geometric basis map (elementary) polytool ? step ›
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from
theta_plus_one_squared of basis-map coefficients of Triangle read by rows: T(n,k) = binomial(k,n-k). shifted by x -> -x…?
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Laguerre’s theorem on multiplier sequences [SP14; Bra15, Thm 7.1 of arXiv:1410.6601] polytool ? step ›
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from
theta_plus_one_squared of basis-map coefficients of Triangle read by rows: T(n,k) = binomial(k,n-k). shifted by x -> -x…?
Related ?
Same fingerprint ?
- A038231: Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j).
- A013611 → D → D
- A038329 → reverse
- A027467 → basis A013611 → reverse
- A013610 → basis A013611 → x ↦ x/(x+1)
- A136572 → θ+1 → basis A013611
- A027467 → basis A013611
- basis-map coefficients of A026729, shifted → D → basis A013611
- A136521 → basis A013611
- A038303 → basis A007318 → basis A013610
- A136572 → basis A013611
- A013611: Triangle of coefficients in expansion of (1+4x)^n.
- basis-map coefficients of A026729 → basis A013611 → reverse
- A130123 → basis A013611
- A130123 → (θ+1)² → basis A013611
- basis-map coefficients of A030528, shifted → basis A013611
- A013611 → D
- basis-map coefficients of A026729 → (θ+1)² → basis A013611
- A038330 → basis A007318 → D
- basis-map coefficients of A112227 → θ+1 → basis A013611
- A038330 → basis A007318 → reverse
- basis-map coefficients of A112227 → basis A013611
- A120910 → basis A007318 → basis A007318
- A038231 → D
- A038330 → basis A007318
- A136572 → basis A013611 → D
- A136572 → basis A013611 → reverse
- A132440 → basis A013611
- basis-map coefficients of A026729, shifted → θ+1 → basis A013611
- basis-map coefficients of A112227 → (θ+1)² → basis A013611
- basis-map coefficients of A026729, shifted → basis A013611
- A136572 → D → basis A013611
- image under θ+1 → (θ+1)² → basis A013611
- A131436 → basis A013611
- A129186 → basis A013611
- basis-map coefficients of A030528, shifted → D → basis A013611
- A038231 → D → D
- basis-map coefficients of A026729 → basis A013611
- A136572 → (θ+1)² → basis A013611
- basis-map coefficients of A112227 → basis A013611 → reverse
- A027466 → basis A013609 → D
- A127648 → D → basis A013611
- A131431 → basis A013611
- A130123 → basis A013611 → D
- basis-map coefficients of A021012 → θ+1 → basis A013611
- A130123 → θ+1 → basis A013611
- basis-map coefficients of A026729 → basis A013611 → D
- A027467 → basis A013611 → D
- image under θ+1 → θ+1 → D → basis A013611
- A131431 → θ+1 → basis A013611
- A132440 → θ+1 → basis A013611
- basis-map coefficients of A026729 → D → basis A013611
- image under θ+1 → basis A013611
- Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*3^j.
- A038329 → D
- basis-map coefficients of A112227 → basis A013611 → D
- basis-map coefficients of A030528, shifted → θ+1 → basis A013611
- basis-map coefficients of A026729, shifted → (θ+1)² → basis A013611
- A027466 → basis A013609
- basis-map coefficients of A021012 → basis A013611
- A134309 → basis A013611
- A130123 → D → basis A013611
- A131431 → D → basis A013611
References
- [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
- [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
- [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.