A154602: Exponential Riordan array [exp(sinh(x)*exp(x)), sinh(x)*exp(x)].

basis-map coefficients of A026729 → basis A154602

A154602 nonnegative coefficients

Proved for all n: all roots real, in (−∞, −1] · coefficients of one sign · Hadamard kernel what this means

Recurrence from OEIS A154602
\(P_{n}(x) = \left(1 + x\right)\,P_{n-1}(x) + \left(2 + 2\,x\right)\,P_{n-1}'(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2112
33418
411199140
54910470161240
62576415501902511664
7153943804531208042536112992
8102993280339515224916265833491112256
975905266768365324247072872061601614846411059840
10609441233750535758202792476119208628119036204246081110827264
1152844512192523636971461326598401633315047196247862827440038551001118758400
124913492321894600340274158139625554122685443077684398159828901963962141735577512111389711360
13487026929231693925646101871544991365808321478939112731774883129574364771008044774072538808338144117258893312
1451209054412587859331355316069874652680629384665624520720975230991600956527611002471481283958399467887432146116741691226463227904
1556878092067304020964876694067320311885442472096694926579711349498569420114503039651245676059203453398377316928612187997817047041592519613127694491648

Generated b-files: A055882 (row sums), A154602 ?

Computed in your browser ?

Technical details
Node id
n-806f02861480e04e · revision 1 · JSON
Definition source
oeis_catalog:A154602
Fingerprint
f6-b3b7fb695f9c1be8

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 -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

OEIS matches ?

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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:      1;
   2:      1,       1;
   3:      3,       4,       1;
   4:     11,      19,       9,       1;
   5:     49,     104,      70,      16,       1;
   6:    257,     641,     550,     190,      25,      1;
   7:   1539,    4380,    4531,    2080,     425,     36,     1;
   8:  10299,   32803,   39515,   22491,    6265,    833,    49,    1;
   9:  75905,  266768,  365324,  247072,   87206,  16016,  1484,   64,  1;
  10: 609441, 2337505, 3575820, 2792476, 1192086, 281190, 36204, 2460, 81, 1;
%F Formula
The row polynomials satisfy P(n,x) = (1+x)*P(n-1,x) + (2+2*x)*d/dx P(n-1,x) for n >= 2, with P(1,x) = 1.
%t Mathematica
P[1, x_] := 1;
P[n_, x_] := P[n, x] = Expand[(1 + x)*P[n - 1, x] + (2 + 2*x)*D[P[n - 1, x], x]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 1; for(n = 2, N, my(i = n); v[i] = (1 + x)*v[i - 1] + (2 + 2*x)*deriv(v[i - 1], x)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

Generated with polytool c48629374597.

A154602: triangle, offset 0, from the row P1
%e Example
Triangle begins:
  0:      1;
  1:      1,       1;
  2:      3,       4,       1;
  3:     11,      19,       9,       1;
  4:     49,     104,      70,      16,       1;
  5:    257,     641,     550,     190,      25,      1;
  6:   1539,    4380,    4531,    2080,     425,     36,     1;
  7:  10299,   32803,   39515,   22491,    6265,    833,    49,    1;
  8:  75905,  266768,  365324,  247072,   87206,  16016,  1484,   64,  1;
  9: 609441, 2337505, 3575820, 2792476, 1192086, 281190, 36204, 2460, 81, 1;
%F Formula
The row polynomials satisfy P(n,x) = (1+x)*P(n-1,x) + (2+2*x)*d/dx P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[(1 + x)*P[n - 1, x] + (2 + 2*x)*D[P[n - 1, x], x]];
Table[PadRight[CoefficientList[P[n, x], x], n + 1], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = (1 + x)*v[i - 1] + (2 + 2*x)*deriv(v[i - 1], x)); v};
row(n, p) = {my(c = Vecrev(p)); c = concat(c, vector(n + 1 - #c)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i - 1, v[i])))};
T(9)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 1, is zero or real-rooted with all roots in (-inf, -1]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-18b4793e32bd250f
  • Coefficients of one sign. Every nonzero row, n >= 1: the coefficients of P_n 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-18b4793e32bd250f
  • Hadamard kernel (Malo). Rows P_n, n >= 1, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-18b4793e32bd250f

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

No candidate equalities or related sequences.

References

  1. [MW08] Shi-Mei Ma and Yi Wang. q-Eulerian polynomials and polynomials with only real zeros. The Electronic Journal of Combinatorics, 15(1):Research Paper 17, January 2008. doi:10.37236/741