Column 3 of triangle A359670; a(n) = A359670(n+3,3) for n >= 0.

Terms

a(0) =1a(1) =20a(2) =170a(3) =970a(4) =4410a(5) =17172a(6) =59545a(7) =188700a(8) =556085a(9) =1542640a(10) =4065868a(11) =10253720a(12) =24880705a(13) =58351000a(14) =132750390a(15) =293867786a(16) =634623035a(17) =1339924290a(18) =2771178885a(19) =5623152080a(20) =11211087225a(21) =21989506510a(22) =42478375740a(23) =80897833810a(24) =152022961870a(25) =282119268256a(26) =517394696690