a(n) = Sum_{k=0..n} C(n,k)^2*T(k)*T(n-k), where T(k) = A002426(k) is the coefficient of x^k in the expansion of (x^2+x+1)^k.
A329475
a(n) = Sum_{k=0..n} C(n,k)^2*T(k)*T(n-k), where T(k) = A002426(k) is the coefficient of x^k in the expansion of (x^2+x+1)^k.
Terms
- a(0) =1a(1) =2a(2) =10a(3) =68a(4) =586a(5) =5252a(6) =49204a(7) =475400a(8) =4723786a(9) =47937812a(10) =494786260a(11) =5177188040a(12) =54794164660a(13) =585565913480
External references
- oeis: A329475