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

A338793

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

Terms

    a(0) =1a(1) =1a(2) =3a(3) =9a(4) =35a(5) =157a(6) =799a(7) =4525a(8) =28131a(9) =189961a(10) =1381731a(11) =10752725a(12) =89024543a(13) =780441893a(14) =7215286619a(15) =70101824033a(16) =713576518099

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