A threes sequence that gets more even factors out: a(n) = (3^n - 1)*(3^n + 1)/2^(4 - (n mod 2)).
A152299
A threes sequence that gets more even factors out: a(n) = (3^n - 1)*(3^n + 1)/2^(4 - (n mod 2)).
Terms
- a(0) =0a(1) =1a(2) =5a(3) =91a(4) =410a(5) =7381a(6) =33215a(7) =597871a(8) =2690420a(9) =48427561a(10) =217924025a(11) =3922632451a(12) =17651846030a(13) =317733228541
External references
- oeis: A152299