a(n) = Sum_{k=0..n} binomial(floor((n+1)/2), floor((k+1)/2)) * 10^k.
A097177
a(n) = Sum_{k=0..n} binomial(floor((n+1)/2), floor((k+1)/2)) * 10^k.
Terms
- a(0) =1a(1) =11a(2) =111a(3) =1221a(4) =11221a(5) =133331a(6) =1133331a(7) =14466441a(8) =114466441a(9) =1561110551a(10) =11561110551a(11) =167672165661
External references
- oeis: A097177