a(n) is the constant term in expansion of Product_{k=1..n} (x^prime(k) + 1 + 1/x^prime(k))^2.
A369388
a(n) is the constant term in expansion of Product_{k=1..n} (x^prime(k) + 1 + 1/x^prime(k))^2.
Terms
- a(0) =1a(1) =3a(2) =9a(3) =45a(4) =249a(5) =1373a(6) =9177a(7) =62257a(8) =453179a(9) =3320531a(10) =24087877a(11) =183643865a(12) =1394580343a(13) =10794949627a(14) =85730722969a(15) =686171829489
External references
- oeis: A369388