A038325 → basis A007318 → θ+1

nonnegative coefficientsonly rational roots

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

Recurrence

\(\left(2 + n x\right)\,P_{n}(x) = \left(44 + 44\,x + 11\,x^{2} + 22\,n x + 11\,n x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
1222244
24849683631815
3106483194423958532471874
42342569370241054152468512732052767149
551536322576816038652240257681608052550966306104361048
611337990468027942412755239201133799040531468300127552392124009273874403907
724943578881746050521639286136736436512630402728203940098215341841909742758155897368142061476590
8548758735364390069882881152393344256153652445900812004097336005761966721281680573627042743793676819292299295156831600217
91207269217792108654229601283259626888038450705307147264475362254505602852173527033611091785938464271635574003238198752594223579476910185645937607812
10265599227914242655992279142408963973942105601593595367485440174299493318720012549563518947846100482266155201991994209356804201862785362051874849202002853116706116636842269479279
1158431830141132864275013155246082410312993321728048206259866434560602578248330432005061657285975628829526334168191168120515649666086403389502646858680627685675344200690454242878623423740047332235863163730725146
12128550026310492161542600315725905926363226302369361921414050289415413760198850821949042560019089678907108085761299158703400411392636322630236936192223707174692672880552363394302896009113996005997784903867372495648407995688973738339447574764924805
13282810057883082752367653075248007577616544388386160340992404418382772808335366319037230825130240068245602092911406592530799127389310940163033137870796062515212796050392420888736394939826926570640086886761923845540812925303426687766411668676704648678483317970015034293548554631725353136
146221821273427820544871054978279894876164246393019114487521281132371471763863339008194626346709414011392023355161605129681367042043576640448847119616133458066315026750668865686392014427228844824328293338676751424066902806681361066416132699781847327735041796976212515896412148861934764630472569624750374861510292546196774870194331
Technical details
Node id
n-78f7c675f6d6e8e6 · revision 0 · JSON
Definition source
derived:theta_plus_one
Fingerprint
f6-e620d4a356abb37c

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:            22,             22;
  2:           484,            968,            363;
  3:         10648,          31944,          23958,           5324;
  4:        234256,         937024,        1054152,         468512,          73205;
  5:       5153632,       25768160,       38652240,       25768160,        8052550,         966306;
  6:     113379904,      680279424,     1275523920,     1133799040,      531468300,      127552392,       12400927;
  7:    2494357888,    17460505216,    39286136736,    43651263040,    27282039400,     9821534184,     1909742758,     155897368;
  8:   54875873536,   439006988288,  1152393344256,  1536524459008,  1200409733600,   576196672128,   168057362704,   27437936768,   1929229929;
  9: 1207269217792, 10865422960128, 32596268880384, 50705307147264, 47536225450560, 28521735270336, 11091785938464, 2716355740032, 381987525942, 23579476910;
%F Formula
The row polynomials satisfy (2+n*x)*P(n,x) = (44+(22*n+44)*x+(11*n+11)*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[((44 + (22*n + 44)*x + (11*n + 11)*x^2)*P[n - 1, x])/(2 + 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] = ((44 + (22*n + 44)*x + (11*n + 11)*x^2)*v[i - 1])/(2 + 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.