G.f.: 1/(1 - 7 x + 15 x^2 - 6 x^3 - 11 x^4 + 6 x^5 + x^6).

Terms

a(0) =1a(1) =7a(2) =34a(3) =139a(4) =516a(5) =1802a(6) =6039a(7) =19657a(8) =62634a(9) =196404a(10) =608361a(11) =1866462a(12) =5683236a(13) =17200871a(14) =51807242a(15) =155421557a(16) =464755958a(17) =1386055506a(18) =4124569714a(19) =12251283960a(20) =36334754000a(21) =107624090145a(22) =318444202635a(23) =941387240040