A038325 → basis A013611

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, 0] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(P_{n}(x) = \left(22 + 44\,x\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1224466
2484193619364356
3106486388812777685184287496
4234256187404856221447496192374809618974736
55153632515363202061452804122905604122905601649162241252332576
611337990413605588486802794240181407846402721117696021768941568725631385682653950016
72494357888349210104322095260625926984202086401396840417280167620850073611174723338243192778096645455160701056
8548758735368780139765766146097836032245843913441286146097836032098337565376512983375653765125619289450086414048223625216360040606269696
91207269217792217308459202561738467673620488112849143562242433854743068672486770948613734464902793148497925563096555585536278154827779276861812183950950423762680013799936
102655992279142453119845582848047807861024563202549752587976704089241340579184640214179217390043136356965362316738560407960414076272640305970310557204480135986804692090880271973609384181761568336880910795776
1158431830141132812855002631049216128550026310492160771300157862952960308520063145181184086385617680650731521727712353613014630424681605051614494720246816050516144947201645440336774299648065817613470971985921196683881290399744103510234140112521216
1212855002631049216308520063145181184339372069459699302422624804630646620160101811620837909790720325797186681311330304760193435589726437376130318874672524532121616289859334065566515201447987496361383690240868792497816830214144315924544660665532416526540907767775887366831675453247426400256
132828100578830827527353061504960151552882367380595218186246470694124364933365763235347062182466682880116472494238568800583683105933179695168015564862118663593903360311296931779953908550404669441035311059898389338521608282488479187114708172845177209886475171135488150590699621583903784962316779994178213904384450890579914330142416896
14622182127342782054417421099565597897523222647429435277266780161811794354822181342412899648689515219973832704398594758060879895330816119578427418263968599244827332211981317478536970244783137096730558743969792637751612897407832529305663775161289740783252930564638193548344784236576768231909677417239211828838471356823820688988255027210193831974384141179289629758778274345789399515136

Computed in your browser ?

Technical details
Node id
n-9805b07a338913cb · revision 1 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-11aec07ce60b6d61

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

OEIS matches ?

No OEIS matches.

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:             1;
  1:            22,             44;
  2:           484,           1936,            1936;
  3:         10648,          63888,          127776,           85184;
  4:        234256,        1874048,         5622144,         7496192,          3748096;
  5:       5153632,       51536320,       206145280,       412290560,        412290560,        164916224;
  6:     113379904,     1360558848,      6802794240,     18140784640,      27211176960,      21768941568,       7256313856;
  7:    2494357888,    34921010432,    209526062592,    698420208640,    1396840417280,    1676208500736,    1117472333824,     319277809664;
  8:   54875873536,   878013976576,   6146097836032,  24584391344128,   61460978360320,   98337565376512,   98337565376512,   56192894500864,   14048223625216;
  9: 1207269217792, 21730845920256, 173846767362048, 811284914356224, 2433854743068672, 4867709486137344, 6490279314849792, 5563096555585536, 2781548277792768, 618121839509504;
%F Formula
The row polynomials satisfy P(n,x) = (22+44*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[(22 + 44*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] = (22 + 44*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)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-6a2839a9935a683b
  • Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
    All coefficients of each polynomial have the same sign (after x -> -x when alternating).
    derived from the cited steps by a stated theorem: e-6a2839a9935a683b
  • Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-6a2839a9935a683b

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

Same fingerprint (67)

Equal up to content, sign, reversal and a small index shift.

References

  1. [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