Abel polynomials

From HandWiki

The Abel polynomials are a sequence of polynomials named after Niels Henrik Abel, defined by the following equation:

pn(x)=x(xan)n1

This polynomial sequence is of binomial type: conversely, every polynomial sequence of binomial type may be obtained from the Abel sequence using umbral calculus.

Examples

For a = 1, the polynomials are (sequence A137452 in the OEIS)

p0(x)=1;
p1(x)=x;
p2(x)=2x+x2;
p3(x)=9x6x2+x3;
p4(x)=64x+48x212x3+x4;

For a = 2, the polynomials are

p0(x)=1;
p1(x)=x;
p2(x)=4x+x2;
p3(x)=36x12x2+x3;
p4(x)=512x+192x224x3+x4;
p5(x)=10000x4000x2+600x340x4+x5;
p6(x)=248832x+103680x217280x3+1440x460x5+x6;

References