A038331 → basis A013610 → x ↦ x+1

nonnegative coefficientsonly rational roots

Proved for all n all roots real, in (−∞, −1]coefficients of one signHadamard kernelinterlacing (weak)

Recurrence

\(P_{n}(x) = \left(32 + 15\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1024 + 960\,x + 225\,x^{2}\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9Pn(1)
010249602252209
13276846080216003375103823
2104857619660801382400432000506254879681
3335544327864320073728000345600008100000759375229345007
410737418243019898880353894400022118400007776000001458000001139062510779215329
53435973836811274289152015854469120012386304000058060800000163296000002551500000170859375506623120463
610995116277764123168604160676457349120063417876480003715891200000139345920000032659200000043740000000256289062523811286661761
735184372088832148434069749760278313880780800304405807104000214035333120000100329062400000313528320000006298560000000738112500000384433593751119130473102767
Technical details
Node id
n-d5d2f240e694c36e · revision 0 · JSON
Definition source
derived:shift_x_plus_one
Fingerprint
f6-bbe11d3a6446c7ec

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:              1024,                960,                225;
  1:             32768,              46080,              21600,               3375;
  2:           1048576,            1966080,            1382400,             432000,              50625;
  3:          33554432,           78643200,           73728000,           34560000,            8100000,             759375;
  4:        1073741824,         3019898880,         3538944000,         2211840000,          777600000,          145800000,           11390625;
  5:       34359738368,       112742891520,       158544691200,       123863040000,        58060800000,        16329600000,         2551500000,         170859375;
  6:     1099511627776,      4123168604160,      6764573491200,      6341787648000,      3715891200000,      1393459200000,       326592000000,       43740000000,        2562890625;
  7:    35184372088832,    148434069749760,    278313880780800,    304405807104000,    214035333120000,    100329062400000,     31352832000000,     6298560000000,      738112500000,      38443359375;
  8:  1125899906842624,   5277655813324800,  11132555231232000,  13915694039040000,  11415217766400000,   6421059993600000,   2508226560000000,   671846400000000,   118098000000000,   12301875000000,    576650390625;
  9: 36028797018963968, 185773484629032960, 435406604599296000, 612290537717760000, 574022379110400000, 376702186291200000, 176579149824000000, 59122483200000000, 13856832000000000, 2165130000000000, 202980937500000, 8649755859375;
%F Formula
The row polynomials satisfy P(n,x) = (32+15*x)*P(n-1,x) for n >= 1, with P(0,x) = 1024 + 960*x + 225*x^2.
%t Mathematica
P[0, x_] := 1024 + 960*x + 225*x^2;
P[n_, x_] := P[n, x] = Expand[(32 + 15*x)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1024 + 960*x + 225*x^2; for(n = 1, N, my(i = n + 1); v[i] = (32 + 15*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 - 1, v[i])))};
T(9)

polytool c48629374597

Properties

Proof chains ? JSON

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.