a(n) = prime(n) * Product_{k=0..n-2} prime(n-k) mod prime(n-k-1).

Terms

a(0) =2a(1) =3a(2) =10a(3) =28a(4) =176a(5) =416a(6) =2176a(7) =4864a(8) =23552a(9) =178176a(10) =380928a(11) =2727936a(12) =12091392a(13) =25362432a(14) =110886912a(15) =750256128a(16) =5011144704a(17) =10362028032a(18) =68287463424a(19) =289457307648a(20) =595222069248