A038330 → basis A013609 → x ↦ x/(x+1)

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(1 + x\right)\,P_{n}(x) = \left(16 + 40\,x + 24\,x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 256 + 768\,x + 576\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
02567685761600
1409618432276481382464000
2655363932168847368847363317762560000
3104857678643202359296035389440265420807962624102400000
416777216150994944566231040113246208012740198407644119041911029764096000000
5268435456281857228812683575296317089382404756340736042807066624214035333124586471424163840000000
64294967296515396075522705829396488117488189441522029035520182643484262413698261319685870683422721100753141766553600000000
76871947673692771293593655662776156161948197165465643834436222976657516543344646575165433446442268920643584158508452413442641807540224262144000000000
Technical details
Node id
n-e5c39a3f8db2de85 · revision 0 · JSON
Definition source
derived:mobius_x_over_x_plus_one
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 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,             768,              576;
  1:           4096,           18432,            27648,            13824;
  2:          65536,          393216,           884736,           884736,            331776;
  3:        1048576,         7864320,         23592960,         35389440,          26542080,           7962624;
  4:       16777216,       150994944,        566231040,       1132462080,        1274019840,         764411904,         191102976;
  5:      268435456,      2818572288,      12683575296,      31708938240,       47563407360,       42807066624,       21403533312,        4586471424;
  6:     4294967296,     51539607552,     270582939648,     811748818944,     1522029035520,     1826434842624,     1369826131968,      587068342272,      110075314176;
  7:    68719476736,    927712935936,    5566277615616,   19481971654656,    43834436222976,    65751654334464,    65751654334464,    42268920643584,    15850845241344,     2641807540224;
  8:  1099511627776,  16492674416640,  111325552312320,  445302209249280,  1168918299279360,  2104052938702848,  2630066173378560,  2254342434324480,  1268067619307520,   422689206435840,    63403380965376;
  9: 17592186044416, 290271069732864, 2177033022996480, 9796648603484160, 29389945810452480, 61718886201950208, 92578329302925312, 99191067110277120, 74393300332707840, 37196650166353920, 11158995049906176, 1521681143169024;
%F Formula
The row polynomials satisfy (1+x)*P(n,x) = (16+40*x+24*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 256 + 768*x + 576*x^2.
%t Mathematica
P[0, x_] := 256 + 768*x + 576*x^2;
P[n_, x_] := P[n, x] = Expand[Together[((16 + 40*x + 24*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 + 768*x + 576*x^2; for(n = 1, N, my(i = n + 1); v[i] = ((16 + 40*x + 24*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.