A136572 → basis A013609 → D

nonnegative coefficientsonly rational roots

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

Recurrence

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

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13Pn(1)
00
122
281624
336144144324
41921152230415365184
51200960028800384001920097200
68640864003456006912006912002764802099520
7705608467204233600112896001693440013547520451584051438240
8645120903168054190080180633600361267200433520640289013760825753601410877440
965318401045094407315660802926264320731566080011705057280117050572806688604160167215104042855402240
107257600013063680001045094400048771072000146313216000292626432000390168576000334430208000167215104000371589120001428513408000
118781696001756339200015807052800084304281600029506498560007081559654400118025994240001348868505600010116513792000449622835200089924567040051855036710400
121149603840025291284480025291284480001517477068800060699082752000169957431705600339914863411200485592662016000485592662016000323728441344000129491376537600235438866432002036488714444800
1316190254080038856609792004274227077120028494847180800012822681231360004103257994035200957426865274880016413031976140800205162899701760001823670219571200010942021317427200397891684270080066315280711680086041648185292800
14244099215360063465795993600761589551923200558499004743680027924950237184000100529820853862400268079522276966400536159044553932800804238566830899200893598407589888000714878726071910400389933850584678400129977950194892800199966077222912003891729933304012800
Technical details
Node id
n-b13c43ab7c0b4b74 · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (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 = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:       0;
  1:       2;
  2:       8,        16;
  3:      36,       144,       144;
  4:     192,      1152,      2304,       1536;
  5:    1200,      9600,     28800,      38400,      19200;
  6:    8640,     86400,    345600,     691200,     691200,      276480;
  7:   70560,    846720,   4233600,   11289600,   16934400,    13547520,     4515840;
  8:  645120,   9031680,  54190080,  180633600,  361267200,   433520640,   289013760,   82575360;
  9: 6531840, 104509440, 731566080, 2926264320, 7315660800, 11705057280, 11705057280, 6688604160, 1672151040;
%F Formula
The row polynomials satisfy (n-1)*P(n,x) = (n^2+2*n^2*x)*P(n-1,x) for n >= 2, with P(0,x) = 0, P(1,x) = 2.
%t Mathematica
P[0, x_] := 0;
P[1, x_] := 2;
P[n_, x_] := P[n, x] = Expand[Together[((n^2 + 2*n^2*x)*P[n - 1, x])/(n - 1)]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 0; v[2] = 2; for(n = 2, N, my(i = n + 1); v[i] = ((n^2 + 2*n^2*x)*v[i - 1])/(n - 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

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.