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A249548 Coefficients of reduced partition polynomials of A134264 for computing Lagrange compositional inversion. 5
1, 0, 1, 1, 1, 2, 1, 5, 1, 6, 3, 5, 1, 7, 7, 21 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

Coefficients of reduced partition polynomials of A134264 for computing the complete partition polynomials for the Lagrange compositional inversion of A134264 (see Oct 2014 comment by Copeland there). Umbrally,

e^(x*t) * exp[Prt(.;1,0,h_2,..) * t] = exp[Prt(.;1,x,h_2,..) * t], where Prt(n;1,0,h_2,..,h_n) are the reduced (h_0 = 1 and h_1 = 0) partition polynomials of the complete polynomials Prt(n;h_0,h_1,h_2,..,h_n) of A134264.

Partitions are given in the order of those on page 831 of Abramowitz and Stegun. Formulas for the coefficients of the partitions are given in A134264.

Row sums are the Motzkin sums or Riordan numbers A005043. - Tom Copeland, Nov 09 2014

LINKS

Table of n, a(n) for n=0..15.

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

FORMULA

From Tom Copeland, Nov 10 2014: (Start)

Terms may be computed symbolically up to order n by using an iterated derivative evaluated at t=0:

with g(t) = 1/{d/dt [t/(1 + 0 t + h_2 t^2 + h_3 t^3 + ... + h_n t^n)]},

evaluate 1/n! * [g(t) d/dt]^n t at t=0, i.e., ask a symbolic math app for the first term in a series expansion of this iterated derivative, to obtain Prt(n-1).

Alternatively, the explicit formula in A134264 for the numerical coefficients of each partition can be used. (End)

From Tom Copeland, Nov 12 2014: (Start)

The first few partitions polynomials formed by taking the reciprocal of the e.g.f. of this entry's e.g.f. (cf. A133314) are

UPrt(0) = 1

UPrt(1;1,0) = 0

UPrt(2;1,0,h_2) = -1 h_2

UPrt(3;1,0,h_2,h_3) = -1 h_3

UPrt(4;1,0,h_2,..,h_4) = -1 h_4 + 4 (h_2)^2

UPrt(5;1,0,h_2,..,h_5) = -1 h_5 + 15 h_2 h_3

UPrt(6;1,0,h_2,..,h_6) = -1 h_6 + 24 h_2 h_4 + 17 (h_3)^2 + -35 (h_2)^3

...

Therefore, umbrally, [Prt(.;1,0,h_2,...) + UPrt(.;1,0,h_2,...)]^n = 0 for n>0 and unity for n=0.

Example of the umbral operation:

(a. +  b.)^2 = a.^2 + 2 a.* b. + b.^2 = a_2 + 2 a_1 * b_1 + b_2.

This implies that the umbral compositional inverses (see below) of the partition polynomials of the Lagrange inversion formula (LIF) of A134264 with h_0=1 are given by UPrt(n;1,h_1,h_2,...,h_n) = [UPrt(.;1,0,h_2,...,h_n) + h_1]^n, so that the sequence of polynomials UPrt(n;1,h_1,h_2,...,h_n) is an Appell sequence in the indeterminate h_1. So, if one calculates UPrt(n;1,h_1,...,h_n), the lower order UPrt(n-1;1,h_1,...,h_(n-1)) can be found by taking the derivative w.r.t. h_1 and dividing by n. Same applies for Prt(n;1,h_1,h_2,...,h_n).

This connects the combinatorics of the permutohedra through A133314 and A049019, or their duals, to the noncrossing partitions, Dyck lattice paths, etc. that are isomorphic with the LIF of A134264.

An Appell sequence P(.,x) with the e.g.f. e^(x*t)/w(t) possesses an umbral inverse sequence UP(.,x) with the e.g.f. w(t)e^(x*t), i.e., polynomials such that P(n,UP(.,x))= x^n = UP(n,P(.,x)) through umbral substitution, as in the binomial example. The Bernoulli polynomials with w(t) = t/(e^t - 1) are a good example with the umbral compositional inverse sequence UP(n,x) = [(x+1)^(n+1)-x^(n+1)] / (n+1) (cf. A074909 and A135278). (End)

EXAMPLE

Prt(0) = 1

Prt(1;1,0) = 0

Prt(2;1,0,h_2) = 1 h_2

Prt(3;1,0,h_2,h_3) = 1 h_3

Prt(4;1,0,h_2,..,h_4) = 1 h_4 + 2 (h_2)^2

Prt(5;1,0,h_2,..,h_5) = 1 h_5 + 5 h_2 h_3

Prt(6;1,0,h_2,..,h_6) = 1 h_6 + 6 h_2 h_4 + 3 (h_3)^2 + 5 (h_2)^3

Prt(7;1,0,h_2,..,h_7) = 1 h_7 + 7 h_3 h_4 + 7 h_2 h_5 + 21 h_3 (h_2)^2

...

------------

With h_n denoted by (n'), the first seven partition polynomials of A134264 with h_0=1 are given by the first seven coefficients of the truncated Taylor series expansion of the Euler binomial transform

e^[(1') * t] * {1 + 1 (2') *  t^2/2! + 1 (3') *  t^3/3! + [1 (4') + 2 (2')^2] *  t^4/4! + [1 (5') + 5 (2')(3')] *  t^5/5! + [1 (6') + 6 (2')(4') + 3 (3')^2 + 5 (2')^3] *  t^6/6!}, giving the truncated expansion

1 + 1 (1') * t + [1 (2') + 1 (1')^2] * t^2/2! + ... + [1 (6') + 6 (1')(5') + 6 (2')(4') + 3 (3')^2 + 15 (1')^2(4') + 30 (1')(2')(3') + 5 (2')^3 + 20 (1')^3(3') + 30 (1')^2(2')^2 + 15 (1')^4(2') + 1 (1')^6] * t^6/6!.

Extending the number of reduced partition polynomials of the transform allows for further complete polynomials of A134264 to be computed.

CROSSREFS

Cf. A134264, A005043, A133314, A049019, A074909, A135278.

Sequence in context: A090080 A151737 A211361 * A014650 A014648 A260147

Adjacent sequences:  A249545 A249546 A249547 * A249549 A249550 A249551

KEYWORD

nonn,more,tabf

AUTHOR

Tom Copeland, Oct 31 2014

EXTENSIONS

Formula for Prt(7,..) and a(12)-a(15) added by Tom Copeland, Jul 22 2016

STATUS

approved

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Last modified May 25 22:22 EDT 2018. Contains 304583 sequences. (Running on oeis4.)