A136572 → θ+1 → basis A008277

nonnegative coefficients

Proved for all n all roots real, in (−∞, 0]coefficients of one signHadamard kernel

Recurrence

\(P_{n}(x) = \left(1 + x + n + n x\right)\,P_{n-1}(x) + \left(x + n x\right)\,P_{n-1}'(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1224
2618630
32416814424360
41201800300012001206240
572022320648004680010800720146160
650403175201517040176400070560010584050404420080
740320512064038949120685843204233600010725120112896040320166924800
836288092534400109771200028195776002522378880960180480167650560130636803628807673823360
93628800185431680033856704000123760224000154314720000828346176002133734400027216000001632960003628800420850080000
103991680040834886400113766871680058178736000009848672064000716454668160025541562816004742115840004610390400021954240003991680027086342976000
11479001600980516275200414460924416002929099574016006607348070400006340314258432003005236878336007617418744320010669760640000816697728000316141056004790016002018319704755200
12622702080025499650176000162914431680000015770116986624000467555919038208005804400370728960035590064128819200118289234359296002238626431641600244877592960000151378875648004857076224006227020800172142484203289600
138717829120071407738321920068781056408064000905934571686144000349367307108019200055302745980658176004300442336526336000182310032262758400044767185848985600065623633057382400575952098641920029352930647040079332244992008717829120016642276683198566400
1413076743680002142362917094400031058586991111680005538779014728960000027561449890630656000055012980989212646400053450056430625254400028327867376320512000087782205735544320000165586228359552000001934675458619904000139228089960960000594991837440000013730580864000013076743680001808459441303074560000
Technical details
Node id
n-9a54acd3eac63e21 · revision 0 · JSON
Definition source
derived:basis_map_A008277
Fingerprint
f6-4732d0911d5a78c5

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): 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 Example
Triangle begins:
  0:       1;
  1:       2,          2;
  2:       6,         18,           6;
  3:      24,        168,         144,           24;
  4:     120,       1800,        3000,         1200,          120;
  5:     720,      22320,       64800,        46800,        10800,         720;
  6:    5040,     317520,     1517040,      1764000,       705600,      105840,        5040;
  7:   40320,    5120640,    38949120,     68584320,     42336000,    10725120,     1128960,      40320;
  8:  362880,   92534400,  1097712000,   2819577600,   2522378880,   960180480,   167650560,   13063680,    362880;
  9: 3628800, 1854316800, 33856704000, 123760224000, 154314720000, 82834617600, 21337344000, 2721600000, 163296000, 3628800;
%F Formula
The row polynomials satisfy P(n,x) = (n+1+(n+1)*x)*P(n-1,x) + (n+1)*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[(n + 1 + (n + 1)*x)*P[n - 1, x] + (n + 1)*x*D[P[n - 1, x], x]];
Table[CoefficientList[P[n, x], x], {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] = (n + 1 + (n + 1)*x)*v[i - 1] + (n + 1)*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 - 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]
  • Coefficients of one sign? Every nonzero row, n ≥ 0: the coefficients of P_n have one sign
    derived from Ray basis map theorem
  • Hadamard kernel (Malo)? Rows P_n, n ≥ 0, are Hadamard kernels (preserve real-rootedness)
    derived from Ray basis map theorem

Proof chains ? JSON

Same fingerprint ?

References

  1. [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
  2. [Bra15] Petter Brändén. Unimodality, log-concavity, real-rootedness and beyond. Handbook of enumerative combinatorics, :437–483, March 2015. doi:10.1201/b18255-10
  3. [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
  4. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.