a(n) = (F(6*n+5) - F(6*n+1))/4 = (F(6*n+4) + F(6*n+2))/4, where F = A000045.

A049629

a(n) = (F(6*n+5) - F(6*n+1))/4 = (F(6*n+4) + F(6*n+2))/4, where F = A000045.

Terms

    a(0) =1a(1) =19a(2) =341a(3) =6119a(4) =109801a(5) =1970299a(6) =35355581a(7) =634430159a(8) =11384387281a(9) =204284540899

External references