A038330 → basis A013611 → x ↦ x/(x+1)

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in [−1, 0]coefficients of one signHadamard kernel

Recurrence

\(\left(1 + x\right)\,P_{n}(x) = \left(16 + 48\,x + 32\,x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 256 + 1024\,x + 1024\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
0256102410242304
14096245764915232768110592
2655365242881572864209715210485765308416
310485761048576041943040838860808388608033554432254803968
4167772162013265921006632960268435456040265318403221225472107374182412230590464
52684354563758096384225485783047516192768015032385536018038862643212025908428834359738368587068342272
642949672966871947673648103633715219241453486084810363371520769658139443276965813944324398046511104109951162777628179280429056
7687194767361236950581248989560464998446179488366592138538465099776277076930199552369435906932736316659348799488158329674399744351843720888321352605460594688
Technical details
Node id
n-8a3a266f7cc7ab95 · revision 0 · JSON
Definition source
derived:mobius_x_over_x_plus_one
Fingerprint
f6-11aec07ce60b6d61

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 2)
  • 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 = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:            256,            1024,             1024;
  1:           4096,           24576,            49152,             32768;
  2:          65536,          524288,          1572864,           2097152,           1048576;
  3:        1048576,        10485760,         41943040,          83886080,          83886080,           33554432;
  4:       16777216,       201326592,       1006632960,        2684354560,        4026531840,         3221225472,         1073741824;
  5:      268435456,      3758096384,      22548578304,       75161927680,      150323855360,       180388626432,       120259084288,        34359738368;
  6:     4294967296,     68719476736,     481036337152,     1924145348608,     4810363371520,      7696581394432,      7696581394432,      4398046511104,      1099511627776;
  7:    68719476736,   1236950581248,    9895604649984,    46179488366592,   138538465099776,    277076930199552,    369435906932736,    316659348799488,    158329674399744,     35184372088832;
  8:  1099511627776,  21990232555520,  197912092999680,  1055531162664960,  3694359069327360,   8866461766385664,  14777436277309440,  16888498602639360,  12666373951979520,   5629499534213120,   1125899906842624;
  9: 17592186044416, 387028092977152, 3870280929771520, 23221685578629120, 92886742314516480, 260082878480646144, 520165756961292288, 743093938516131840, 743093938516131840, 495395959010754560, 198158383604301824, 36028797018963968;
%F Formula
The row polynomials satisfy (1+x)*P(n,x) = (16+48*x+32*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 256 + 1024*x + 1024*x^2.
%t Mathematica
P[0, x_] := 256 + 1024*x + 1024*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((16 + 48*x + 32*x^2)*P[n - 1, x])/(1 + x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 256 + 1024*x + 1024*x^2; for(n = 1, N, my(i = n + 1); v[i] = ((16 + 48*x + 32*x^2)*v[i - 1])/(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

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