basis-map coefficients of A112227 → basis A013609 → D

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(n\right)\,P_{n}(x) = \left(1 + 2\,x + n + 2\,n x\right)\,P_{n-1}(x)\)
\(P_{1}(x) = 4 + 8\,x\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14x15Pn(1)
14812
26242454
38489664216
41080240320160810
5121204809609603842916
61416884022403360268889610206
716224134444808960107527168204834992
81828820168064201603225632256184324608118098
9203602880134404032080640107520921604608010240393660
102244039602112073920177408295680337920253440112640225281299078
112452852803168012672035481670963210137601013760675840270336491524251528
12266246864457602059206589441537536263577632947202928640175718463897610649613817466
132872887366406432032011531523075072615014492252161025024082001924472832149094422937644641044
14308401092087360480480192192057657601317888023063040307507203075072022364160111820803440640491520143489070
1532960134401164806988803075072102502402635776052715520820019209840230489456640596377602752512078643201048576459165024
Technical details
Node id
n-c1bb379fae9335fa · revision 0 · JSON
Definition source
derived:derivative
Fingerprint
f6-11aec07ce60b6d61

Observed on the stored rows ?

  • Degrees: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 (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 = 1, …, ascending powers of x
%e Example
Triangle begins:
   1:  4,   8;
   2:  6,  24,   24;
   3:  8,  48,   96,    64;
   4: 10,  80,  240,   320,   160;
   5: 12, 120,  480,   960,   960,    384;
   6: 14, 168,  840,  2240,  3360,   2688,    896;
   7: 16, 224, 1344,  4480,  8960,  10752,   7168,   2048;
   8: 18, 288, 2016,  8064, 20160,  32256,  32256,  18432,   4608;
   9: 20, 360, 2880, 13440, 40320,  80640, 107520,  92160,  46080,  10240;
  10: 22, 440, 3960, 21120, 73920, 177408, 295680, 337920, 253440, 112640, 22528;
%F Formula
The row polynomials satisfy n*P(n,x) = (n+1+(2*n+2)*x)*P(n-1,x) for n >= 2, with P(1,x) = 4 + 8*x.
%t Mathematica
P[1, x_] := 4 + 8*x;
P[n_, x_] := P[n, x] = Expand[Together[((n + 1 + (2*n + 2)*x)*P[n - 1, x])/(n)]];
Table[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N)); v[1] = 4 + 8*x; for(n = 2, N, my(i = n); v[i] = ((n + 1 + (2*n + 2)*x)*v[i - 1])/(n)); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};
T(10)

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. [SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.