a(0) = 1; a(n) = 3 * Sum_{k=1..n} binomial(n,k) * a(k-1).
A343975
a(0) = 1; a(n) = 3 * Sum_{k=1..n} binomial(n,k) * a(k-1).
Terms
- a(0) =1a(1) =3a(2) =15a(3) =81a(4) =489a(5) =3237a(6) =23211a(7) =178707a(8) =1467051a(9) =12768345a(10) =117263829a(11) =1131901521a(12) =11444383251a(13) =120847326879
External references
- oeis: A343975