a(n) = Sum_{r>0,s>0} binomial(r*s-1,n-1)/2^(r+s).
A123114
a(n) = Sum_{r>0,s>0} binomial(r*s-1,n-1)/2^(r+s).
Terms
- a(0) =1a(1) =3a(2) =13a(3) =83a(4) =701a(5) =7363a(6) =92541a(7) =1354627a(8) =22636861a(9) =425241347a(10) =8871085565a(11) =203487078403
External references
- oeis: A123114