0,3

It would be nice to have a formula for the 2^(n-1)th coefficient.

The exponent of x in P(n) with a(n) as coefficient is {1,1,2,5,9,19,37,74,147,294,587,1175,...}.

(PARI) P(n)=if(n<1, x, P(n-1)*(P(n-1)+1))

(PARI) a(n)=vecmax(Vec(P(n)))

Cf. A016131.

Sequence in context: A161181 A073834 A111837 this_sequence A079278 A015178 A013034

Adjacent sequences: A092120 A092121 A092122 this_sequence A092124 A092125 A092126

nonn

Ralf Stephan, Apr 02 2004