basis-map coefficients of A026729 → basis A013609 → basis A013609

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(3 + 4\,x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
111
2347
39241649
42710814464343
5814328647682562401
62431620432057603840102416807
77295832194403456034560184324096117649
8218720412816481814402419201935368601616384823543
9656169984326592870912145152015482881032192393216655365764801
10196832361961259712391910478382081045094492897285308416176947226214440353607
1159049787320472392016796160391910406270566469672960530841602654208078643201048576282475249
12177147259815617321040692841601847577603448811524598415364379443202919628801297612803460300841943041977326743
13531441850305662355744277136640831409920177367449627590492163153199104262766592015571353606228541441509949441677721613841287201
1415943232763493222107945610808328963602776320864666316815371845632204957941762049579417615182069760809710387229444014086543114246710886496889010407
1547829698928208877377809641268165121513166054440351094784807021895681229747650561434705592321275293859848501959065641221619712137405399042818572288268435456678223072849
Technical details
Node id
n-7b019d2b851f98f1 · revision 0 · JSON
Definition source
derived:basis_map_A013609
Fingerprint
f6-c91d5d506c107735

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): yes

Matches ?

No OEIS matches.

Submission text ?

Atlas rows n = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:     1;
   2:     3,      4;
   3:     9,     24,      16;
   4:    27,    108,     144,      64;
   5:    81,    432,     864,     768,     256;
   6:   243,   1620,    4320,    5760,    3840,     1024;
   7:   729,   5832,   19440,   34560,   34560,    18432,    4096;
   8:  2187,  20412,   81648,  181440,  241920,   193536,   86016,   16384;
   9:  6561,  69984,  326592,  870912, 1451520,  1548288, 1032192,  393216,   65536;
  10: 19683, 236196, 1259712, 3919104, 7838208, 10450944, 9289728, 5308416, 1769472, 262144;
%F Formula
The row polynomials satisfy P(n,x) = (3+4*x)*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[(3 + 4*x)*P[n - 1, 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] = (3 + 4*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, v[i])))};
T(10)

polytool c48629374597

Properties

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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.