A156992 → basis A007318 → x ↦ x+1

nonnegative coefficientsonly rational roots

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

Recurrence

\(P_{n}(x) = \left(3 + x + 3\,n + n x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1628
25436696
3648648216241536
49720129606480144012030720
51749602916001944006480010800720737280
6367416073483206123600272160068040090720504020643840
78817984020575296020575296011430720038102400762048084672040320660602880
82380855680634894848074071065604938071040205752960054867456091445760870912036288023781703680
9714256704002142770112002857026816002222131968001111065984003703553280082301184001175731200979776003628800951268147200
10235704712320078568237440001178523561600010475764992000611086291200024443451648006789847680001293304320001616630400011975040003991680041855798476800
118485369643520031113022026240051855036710400051855036710400034570024473600016132678087680053775593625600128037127680002133952128000237105792000158070528004790016002009078326886400
1233092941609728001323717664389120024268157180467200269646190894080002022346431705600010785847635763200419449630279680011984275150848002496723989760003698850355200036988503552002241727488006227020800104472072998092800
13138990354760857600602291537297049600120458307459409920014722682022816768001226890168568064000736134101140838400327170711618150400109056903872716800272642259681792005048930734848000673190764646400611991604224003399953356800871782912005850436087893196800
14625456596423859200029187974499780096000632406114161902080008432081522158694400077294080619788032000515293870798586880002576469353992934400098151213485445120002862743726658816000636165272590848000106027545431808000128518236887040001070985307392000549223234560001307674368000351026165273591808000
Technical details
Node id
n-03dee6c6d6a96425 · revision 0 · JSON
Definition source
derived:shift_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:           6,            2;
  2:          54,           36,            6;
  3:         648,          648,          216,           24;
  4:        9720,        12960,         6480,         1440,          120;
  5:      174960,       291600,       194400,        64800,        10800,         720;
  6:     3674160,      7348320,      6123600,      2721600,       680400,       90720,       5040;
  7:    88179840,    205752960,    205752960,    114307200,     38102400,     7620480,     846720,      40320;
  8:  2380855680,   6348948480,   7407106560,   4938071040,   2057529600,   548674560,   91445760,    8709120,   362880;
  9: 71425670400, 214277011200, 285702681600, 222213196800, 111106598400, 37035532800, 8230118400, 1175731200, 97977600, 3628800;
%F Formula
The row polynomials satisfy P(n,x) = (3*n+3+(n+1)*x)*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[(3*n + 3 + (n + 1)*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] = 1; for(n = 1, N, my(i = n + 1); v[i] = (3*n + 3 + (n + 1)*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

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.