A178821 → 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

\(\left(n + n x\right)\,P_{n}(x) = \left(8 + 32\,x + 24\,x^{2} + 2\,n + 8\,n x + 6\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1103040
260360540960
328025207560756017920
41120134406048012096090720286720
5403260480362880108864016329609797764128768
613440241920181440072576001632960019595520979776055050240
74224088704079833603991680011975040021555072021555072092378880692060160
81267203041280319334401916006407185024001724405760258660864022170931208314099208304721920
93660809884160118609920830269440373621248011208637440224172748802882221056021616657920720555264095965675520
1010250243075072041513472033210777601743565824062768369664156920924160269007298560302633210880201755473920605266421761074815565824
1127955209225216013837824001245404160074724249600313841848320941525544960201755473920030263321088003026332108800181579926528049521798144011725260718080
1274547202683699204428103680442810368002988969984001434705592320502146957312012912350330880242106568704003228087582720029052788244480158469754060803961743851520125069447659520
131949696076038144013686865920150555525120112916643840060974987673602438999506944073169985208320164632466718720274387444531200329264933437440269398581903360134699290951680310844517580801308418837053440
14501350402105671680410605977604927271731204064999178240243899950694401097549778124803763027810713609877948003123201975589600624640296338440093696032327829828403202424587237130240111904026329088023979434213376013458022323978240
Technical details
Node id
n-f72fb87491203488 · revision 0 · JSON
Definition source
derived:mobius_x_over_x_plus_one
Fingerprint
f6-f9762973ec1089d7

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 0)
  • 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:      1;
  1:     10,      30;
  2:     60,     360,       540;
  3:    280,    2520,      7560,      7560;
  4:   1120,   13440,     60480,    120960,      90720;
  5:   4032,   60480,    362880,   1088640,    1632960,      979776;
  6:  13440,  241920,   1814400,   7257600,   16329600,    19595520,     9797760;
  7:  42240,  887040,   7983360,  39916800,  119750400,   215550720,   215550720,    92378880;
  8: 126720, 3041280,  31933440, 191600640,  718502400,  1724405760,  2586608640,  2217093120,   831409920;
  9: 366080, 9884160, 118609920, 830269440, 3736212480, 11208637440, 22417274880, 28822210560, 21616657920, 7205552640;
%F Formula
The row polynomials satisfy (n+n*x)*P(n,x) = (2*n+8+(8*n+32)*x+(6*n+24)*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[Together[((2*n + 8 + (8*n + 32)*x + (6*n + 24)*x^2)*P[n - 1, x])/(n + n*x)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = ((2*n + 8 + (8*n + 32)*x + (6*n + 24)*x^2)*v[i - 1])/(n + n*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.