a(n) is the constant term in expansion of Product_{k=1..n} (x^(2*k-1) + 1 + 1/x^(2*k-1))^2.
A369387
a(n) is the constant term in expansion of Product_{k=1..n} (x^(2*k-1) + 1 + 1/x^(2*k-1))^2.
Terms
- a(0) =1a(1) =3a(2) =9a(3) =43a(4) =243a(5) =1539a(6) =10557a(7) =75595a(8) =558117a(9) =4218077a(10) =32466849a(11) =253624579a(12) =2005655781a(13) =16024596491a(14) =129159081787
External references
- oeis: A369387