A048176: Triangle read by rows: T(n, m) = S1(n, m)*10^(n-m), where S1 are the signed Stirling numbers of first kind A008275 (n >= 1, 1 <= m <= n).
A028338 → x ↦ (−1/5)x+1
A048176 only rational roots
Proved for all n: all roots real, in [5, ∞) · alternating coefficient signs · interlacing (weak) what this means
Rows ?
| n | x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | Pn(1) |
|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 1 | |||||||
| 1 | -10 | 1 | -9 | ||||||
| 2 | 200 | -30 | 1 | 171 | |||||
| 3 | -6000 | 1100 | -60 | 1 | -4959 | ||||
| 4 | 240000 | -50000 | 3500 | -100 | 1 | 193401 | |||
| 5 | -12000000 | 2740000 | -225000 | 8500 | -150 | 1 | -9476649 | ||
| 6 | 720000000 | -176400000 | 16240000 | -735000 | 17500 | -210 | 1 | 559122291 | |
| 7 | -50400000000 | 13068000000 | -1313200000 | 67690000 | -1960000 | 32200 | -280 | 1 | -38579438079 |
Generated b-files: A048176 ?
Computed in your browser ?
Technical details
- Node id
n-f45d29a8d57e6cc8· revision 1 · JSON- Definition source
oeis_catalog:A048176- Fingerprint
f6-0f5f9e74c0cf88d5
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
OEIS matches ?
- A048176: triangle, 38 terms agree, 8 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: -10, 1; 2: 200, -30, 1; 3: -6000, 1100, -60, 1; 4: 240000, -50000, 3500, -100, 1; 5: -12000000, 2740000, -225000, 8500, -150, 1; 6: 720000000, -176400000, 16240000, -735000, 17500, -210, 1; 7: -50400000000, 13068000000, -1313200000, 67690000, -1960000, 32200, -280, 1; 8: 4032000000000, -1095840000000, 118124000000, -6728400000, 224490000, -4536000, 54600, -360, 1; 9: -362880000000000, 102657600000000, -11727000000000, 723680000000, -26932500000, 632730000, -9450000, 87000, -450, 1;
%F FormulaThe row polynomials satisfy P(n,x) = -(10*n-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[-(10*n - x)*P[n - 1, x]];
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] = -(10*n - x)*v[i - 1]); 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.
A048176: triangle, offset 1, from the row P0
%e ExampleTriangle begins: 1: 1; 2: -10, 1; 3: 200, -30, 1; 4: -6000, 1100, -60, 1; 5: 240000, -50000, 3500, -100, 1; 6: -12000000, 2740000, -225000, 8500, -150, 1; 7: 720000000, -176400000, 16240000, -735000, 17500, -210, 1; 8: -50400000000, 13068000000, -1313200000, 67690000, -1960000, 32200, -280, 1; 9: 4032000000000, -1095840000000, 118124000000, -6728400000, 224490000, -4536000, 54600, -360, 1; 10: -362880000000000, 102657600000000, -11727000000000, 723680000000, -26932500000, 632730000, -9450000, 87000, -450, 1;
%F FormulaThe row polynomials satisfy P(n,x) = -(10*n-10-x)*P(n-1,x) for n >= 2, with P(1,x) = 1.
%t MathematicaP[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[-(10*n - 10 - x)*P[n - 1, x]];
Table[PadRight[CoefficientList[P[n, x], x], n], {n, 1, 10}] // Flatten%o PARI/GPP(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = -(10*n - 10 - x)*v[i - 1]); 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
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Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in [5, +inf)
Every polynomial of the sequence has only real roots, inside the stated interval.by the cited steps:
e-040c826eba4e7d74 -
Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n(-x) have one sign
All coefficients of each polynomial have the same sign (after x -> -x when alternating).derived from the cited steps by a stated theorem:
e-040c826eba4e7d74 -
Interlacing of consecutive rows. Rows P_(m-1), P_m interlace (weak, unordered) for every m >= 1
The roots of consecutive polynomials alternate on the real line.by the cited steps:
e-040c826eba4e7d74
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
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preserver_image affine, shift 0
e-040c826eba4e7d74Affine, reversal and Möbius substitutions (elementary) polytool ?
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premise (sequence):
Triangle of coefficients in expansion of (x+1)*(x+3)*...*(x + 2n - 1) in rising powers of x.
uses: Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
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theorem_check liu_wang
e-59b849691f316c6froot: theorem checkLiu–Wang theorem [LW07, Thm 2.1, Cor 2.4] ?
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parent_provers root_domain
e-ef36674c01230a86root: theorem checkParent-row provers of polytool polytool ?
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premise (sequence):
Triangle of coefficients in expansion of (x+1)*(x+3)*...*(x + 2n - 1) in rising powers of x.
Used in 2 proof steps
e-cdcdb3aca64a476dobreschkoff_combination → obreschkoff_combination of Triangle read by rows: T(n, m) = S1(n, m)*10^(n-m), where S1 a…e-cdcdb3aca64a476dobreschkoff_combination → obreschkoff_combination of Triangle read by rows: T(n, m) = S1(n, m)*10^(n-m), where S1 a…
Related sequences ?
No candidate equalities or related sequences.
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