a(n) = product of primes p such that floor(n/p) is odd.

Terms

a(0) =1a(1) =2a(2) =6a(3) =3a(4) =15a(5) =10a(6) =70a(7) =35a(8) =105a(9) =42a(10) =462a(11) =77a(12) =1001a(13) =286a(14) =4290a(15) =2145a(16) =36465a(17) =24310a(18) =461890a(19) =46189a(20) =969969a(21) =176358a(22) =4056234a(23) =676039a(24) =3380195a(25) =520030a(26) =1560090a(27) =111435a(28) =3231615a(29) =430882