a(n) = least k such that both the sum of the smallest n divisors of k and the sum of its greatest n divisors are prime numbers.
A290169
a(n) = least k such that both the sum of the smallest n divisors of k and the sum of its greatest n divisors are prime numbers.
Terms
- a(0) =2a(1) =4a(2) =30a(3) =16a(4) =140a(5) =64a(6) =264a(7) =144a(8) =336a(9) =525a(10) =144a(11) =800a(12) =1200a(13) =576a(14) =1600a(15) =2016a(16) =1440a(17) =1296a(18) =2160a(19) =2304a(20) =7980a(21) =6440a(22) =3360a(23) =8360a(24) =4080a(25) =3960a(26) =2772a(27) =16100a(28) =9108a(29) =10608
External references
- oeis: A290169