a(n) is the constant term in expansion of Product_{ k = 1..n } (x^k + 1/x^k)^3.
A124995
a(n) is the constant term in expansion of Product_{ k = 1..n } (x^k + 1/x^k)^3.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =62a(4) =332a(5) =0a(6) =0a(7) =80006a(8) =531524a(9) =0a(10) =0a(11) =173607568a(12) =1226700784a(13) =0a(14) =0a(15) =455805857978a(17) =0a(18) =0a(21) =0a(22) =0a(25) =0a(26) =0
External references
- oeis: A124995