a(n) = sum of absolute-valued coefficients of (1+2*x-4*x^2)^n.
A084779
a(n) = sum of absolute-valued coefficients of (1+2*x-4*x^2)^n.
Terms
- a(0) =1a(1) =7a(2) =41a(3) =207a(4) =1313a(5) =7807a(6) =42593a(7) =232463a(8) =1290433a(9) =7604415a(10) =42034721a(11) =236031231a(12) =1363681121a(13) =7457831007a(14) =39670144513a(15) =231087069823
External references
- oeis: A084779