G.f. = (1-3*x+x^2)^3*(1+3*x+x^2)^3*(1-x^2)^10/((1-4*x-x^2)*(1-x-x^2)^6*(1+x-x^2)^9).
A324486
G.f. = (1-3*x+x^2)^3*(1+3*x+x^2)^3*(1-x^2)^10/((1-4*x-x^2)*(1-x-x^2)^6*(1+x-x^2)^9).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =22a(4) =53a(5) =319a(6) =1222a(7) =5357a(8) =22814a(9) =95711a(10) =409402a(11) =1723313a(12) =7327733a(13) =30977386a(14) =131351989a(15) =556154467a(16) =2356344131a(17) =9980896486a(18) =42280500142a(19) =179102657228a(20) =758687704322
External references
- oeis: A324486