A137157 - OEIS

%I #7 Jan 04 2023 18:17:11

%S 1,2,5,24,239,4920,206727,17568408,3003763243,1030272816360,

%T 707851744149198,973425618916674288,2678332881795756783639,

%U 14741522294008025924154864,162290544340043699103996962253,3573515596966915773419766367302288,157376160486791180710467411977740266927

%N G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^(2*2^n).

%C Equals unsigned column 1 of triangle A137156.

%o (PARI) {a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+x+x*O(x^n))^(2^(k+1)) ), n)}

%Y Cf. A137156; A001192, A137158, A137159, A137160.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Jan 24 2008

%E a(15)-a(16) from _Alois P. Heinz_, Jan 04 2023