a(n) = Sum_{k=0..n} binomial(floor((n+1)/2), floor((k+1)/2)) * 5^k.
A097176
a(n) = Sum_{k=0..n} binomial(floor((n+1)/2), floor((k+1)/2)) * 5^k.
Terms
- a(0) =1a(1) =6a(2) =31a(3) =186a(4) =811a(5) =5466a(6) =21091a(7) =157746a(8) =548371a(9) =4492026a(10) =14257651a(11) =126558306a(12) =370698931a(13) =3534656586a(14) =9638172211a(15) =98004586866a(16) =250592477491
External references
- oeis: A097176