basis-map coefficients of A112227 → x ↦ x+1 → basis A013610

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(2 + 3\,x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 4 + 12\,x + 9\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14x15x16Pn(1)
1412925
28365427125
3169621621681625
43224072010808102433125
564576216043204860291672915625
61281344604815120226802041210206218778125
7256307216128483849072010886481648349926561390625
8512691241472145152326592489888489888314928118098196831953125
910241536010368041472010886401959552244944020995201180980393660590499765625
10204833792253440114048034214407185024107775361154736086605204330260129907817714748828125
114096737286082563041280102643202463436843110144554273285196312034642080155889364251528531441244140625
128192159744143769679073282965248080061696160123392240185088270208224225173520135104112552698641381746615943231220703125
131638434406433546242012774483026944249080832560431872960740352126097171212609717129457287845158520641934445244464104447829696103515625
143276873728077414405031936022643712074724249618681062403602776320540416448063048585605674372704386889048019344452406696156601434890701434890730517578125
1565536157286417694720123863040603832320217379635259779399681280987136021616657920288222105603026332108824760899072154755619207142567040229582512045916502443046721152587890625
Technical details
Node id
n-ba266de4de1b96ae · revision 0 · JSON
Definition source
derived:basis_map_A013610
Fingerprint
f6-f06e51c139cfae05

Observed on the stored rows ?

  • Degrees: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 (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:    4,    12,      9;
   2:    8,    36,     54,      27;
   3:   16,    96,    216,     216,      81;
   4:   32,   240,    720,    1080,     810,     243;
   5:   64,   576,   2160,    4320,    4860,    2916,      729;
   6:  128,  1344,   6048,   15120,   22680,   20412,    10206,     2187;
   7:  256,  3072,  16128,   48384,   90720,  108864,    81648,    34992,    6561;
   8:  512,  6912,  41472,  145152,  326592,  489888,   489888,   314928,  118098,   19683;
   9: 1024, 15360, 103680,  414720, 1088640, 1959552,  2449440,  2099520, 1180980,  393660,   59049;
  10: 2048, 33792, 253440, 1140480, 3421440, 7185024, 10777536, 11547360, 8660520, 4330260, 1299078, 177147;
%F Formula
The row polynomials satisfy P(n,x) = (2+3*x)*P(n-1,x) for n >= 2, with P(1,x) = 4 + 12*x + 9*x^2.
%t Mathematica
P[1, x_] := 4 + 12*x + 9*x^2;
P[n_, x_] := P[n, x] = Expand[(2 + 3*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] = 4 + 12*x + 9*x^2; for(n = 2, N, my(i = n); v[i] = (2 + 3*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.