a(1) = 2; a(n) is twice the previous term if it is prime, otherwise the previous term minus its lowest prime factor plus one.
A180625
a(1) = 2; a(n) is twice the previous term if it is prime, otherwise the previous term minus its lowest prime factor plus one.
Terms
- a(0) =2a(1) =4a(2) =3a(3) =6a(4) =5a(5) =10a(6) =9a(7) =7a(8) =14a(9) =13a(10) =26a(11) =25a(12) =21a(13) =19a(14) =38a(15) =37a(16) =74a(17) =73a(18) =146a(19) =145a(20) =141a(21) =139a(22) =278a(23) =277a(24) =554a(25) =553a(26) =547a(27) =1094a(28) =1093a(29) =2186
External references
- oeis: A180625