OFFSET
0,2
FORMULA
G.f.: Sum_{n>=0} x^n/(1-x)^(2^n). - Paul D. Hanna, Sep 15 2009
G.f.: Sum_{n>=0} ( (-log(1 - x))^n / n! ) / (1 - 2^n*x). - Paul D. Hanna, Jan 23 2021
MATHEMATICA
Table[Sum[Binomial[2^(n-k) + k - 1, k], {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Jan 23 2021 *)
PROG
(PARI) a(n)=sum(k=0, n, binomial(2^k+n-k-1, n-k))
(PARI) {a(n)=local(A=sum(k=0, n, x^k/(1-x+x*O(x^n))^(2^k))); polcoeff(A, n)} \\ Paul D. Hanna, Sep 15 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 24 2008
STATUS
approved