A137338: Triangle read by rows: T(n,k), 0 <= k <= n, gives the coefficients of the Charlier polynomials (with parameter a=1), ordered by rising powers.
Proved for all n: all roots real · interlacing what this means
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 1 | |||||||
| 1 | -1 | 1 | 0 | ||||||
| 2 | 0 | -3 | 1 | -2 | |||||
| 3 | 3 | 6 | -6 | 1 | 4 | ||||
| 4 | -12 | -9 | 26 | -10 | 1 | -4 | |||
| 5 | 45 | 3 | -109 | 71 | -15 | 1 | -4 | ||
| 6 | -198 | 81 | 501 | -475 | 155 | -21 | 1 | 44 | |
| 7 | 1071 | -786 | -2663 | 3329 | -1455 | 295 | -28 | 1 | -236 |
Generated b-files: A137338 ?
Computed in your browser ?
Technical details
- Node id
n-4ae73ef2b17633d9· revision 1 · JSON- Definition source
oeis_catalog:A137338- Fingerprint
f6-3035e5d369303ab1
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): no
OEIS matches ?
- A137338: triangle, 58 terms agree, 10 full rows row-aligned (tabl) in polytool catalog · view at the OEIS · generated b-file 990 terms from n = 1 ?
A generated b-file is computed from the node's definition along the row alignment of its OEIS link and starts at the entry's offset. It is an identification on a finite prefix, not a proof that the node and the OEIS entry agree for every n.
OEIS submission text ?
Fields to paste into an OEIS submission: the example %e, the formula
%F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows.
For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched;
the matched terms were compared with the published ones, which identifies the node with the entry on a
finite prefix, not for every n. The PARI/GP program is not machine-checked here.
The atlas's own rows: n = 0, …, ascending powers of x
%e ExampleTriangle begins: 0: 1; 1: -1, 1; 2: 0, -3, 1; 3: 3, 6, -6, 1; 4: -12, -9, 26, -10, 1; 5: 45, 3, -109, 71, -15, 1; 6: -198, 81, 501, -475, 155, -21, 1; 7: 1071, -786, -2663, 3329, -1455, 295, -28, 1; 8: -6984, 6711, 16510, -25495, 13729, -3647, 511, -36, 1; 9: 53217, -60309, -117912, 216004, -135961, 43897, -7994, 826, -45, 1;
%F FormulaThe row polynomials satisfy P(n,x) = -(n-x)*P(n-1,x) - n*P(n-2,x) for n >= 2, with P(0,x) = 1, P(1,x) = -1 + x.
%t MathematicaP[0, x_] := 1;
P[1, x_] := -1 + x;
P[n_, x_] := P[n, x] = Expand[-(n - x)*P[n - 1, x] - n*P[n - 2, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten%o PARI/GPP(N) = {my(v = vector(N + 1)); v[1] = 1; v[2] = -1 + x; for(n = 2, N, my(i = n + 1); v[i] = -(n - x)*v[i - 1] - n*v[i - 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)Generated with polytool c48629374597.
A137338: triangle, offset 1, from the row P0
%e ExampleTriangle begins: 1: 1; 2: -1, 1; 3: 0, -3, 1; 4: 3, 6, -6, 1; 5: -12, -9, 26, -10, 1; 6: 45, 3, -109, 71, -15, 1; 7: -198, 81, 501, -475, 155, -21, 1; 8: 1071, -786, -2663, 3329, -1455, 295, -28, 1; 9: -6984, 6711, 16510, -25495, 13729, -3647, 511, -36, 1; 10: 53217, -60309, -117912, 216004, -135961, 43897, -7994, 826, -45, 1;
%F FormulaThe row polynomials satisfy P(n,x) = -(n-1-x)*P(n-1,x) - (n-1)*P(n-2,x) for n >= 3, with P(1,x) = 1, P(2,x) = -1 + x.
%t MathematicaP[1, x_] := 1;
P[2, x_] := -1 + x;
P[n_, x_] := P[n, x] = Expand[-(n - 1 - x)*P[n - 1, x] - (n - 1)*P[n - 2, x]];
Table[PadRight[CoefficientList[P[n, x], x], n], {n, 1, 10}] // Flatten%o PARI/GPP(N) = {my(v = vector(N)); v[1] = 1; v[2] = -1 + x; for(n = 3, N, my(i = n); v[i] = -(n - 1 - x)*v[i - 1] - (n - 1)*v[i - 2]); v};
row(n, p) = {my(c = Vecrev(p)); c = concat(c, vector(n - #c)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)Generated with polytool c48629374597.
Proved properties
-
Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, +inf)
Every polynomial of the sequence has only real roots, inside the stated interval.by the cited steps:
e-fe1ae6008805b5f0 -
Interlacing of consecutive rows. Rows P_(m-1), P_m interlace (strict, previous interlaces next) for every m >= 1
The roots of consecutive polynomials alternate on the real line.by the cited steps:
e-fe1ae6008805b5f0
Proof chains
1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON
-
theorem_check three_term_recurrence
e-fe1ae6008805b5f0root: theorem checkThree-term recurrence criterion [Sze39, §3.3; Fav35] polytool ?
Used in 3 proof steps
e-5aedd40a059ef120preserver_image (affine, shift 0) → shift_x_plus_one of Triangle read by rows: T(n,k), 0 <= k <= n, gives the coefficients of…e-6aed627db0c42e8bpreserver_image (derivative_polynomial, shift 0) → one_plus_derivative of Triangle read by rows: T(n,k), 0 <= k <= n, gives the coefficients…e-c9e97b9a66627f15preserver_image (derivative_polynomial, shift 0) → derivative of Triangle read by rows: T(n,k), 0 <= k <= n, gives the coefficients of the C…
Related sequences ?
No candidate equalities or related sequences.
References
- [Fav35] Jean Favard. Sur les polynômes de tchebicheff. C. R. Acad. Sci. Paris, 200:2052–2053, 1935.
- [Sze39] G. Szegő. Orthogonal Polynomials. Colloquium publications, American Mathematical Society, 1939. doi:10.1090/coll/023