a(1) = 2; for n > 1 if n mod 3=0 a(n) = gpf(1 + Product_{m modulo 3=2,m<n} a(m)), if n modulo 3=1 a(n) = gpf(1 + Product_{m modulo 3=0,m<n} a(m)), if n modulo 3=2 a(n) = gpf(1 + Product_{m modulo 3=1,m<n} a(m)).
A260724
a(1) = 2; for n > 1 if n mod 3=0 a(n) = gpf(1 + Product_{m modulo 3=2,m<n} a(m)), if n modulo 3=1 a(n) = gpf(1 + Product_{m modulo 3=0,m<n} a(m)), if n modulo 3=2 a(n) = gpf(1 + Product_{m modulo 3=1,m<n} a(m)).
Terms
- a(0) =2a(1) =3a(2) =2a(3) =7a(4) =5a(5) =2a(6) =31a(7) =3a(8) =109a(9) =13a(10) =97a(11) =83a(12) =8731a(13) =461a(14) =3078769a(15) =574933a(16) =206179a(17) =510583a(18) =5153873111a(19) =1900169a(20) =372828179
External references
- oeis: A260724