Least prime k>1 such that the sum of divisors of powers k^e, 1 <= e <= n, are divisible by the number their divisors, d(k^e).
A272981
Least prime k>1 such that the sum of divisors of powers k^e, 1 <= e <= n, are divisible by the number their divisors, d(k^e).
Terms
- a(0) =3a(1) =7a(2) =7a(3) =31a(4) =31a(5) =211a(6) =211a(7) =211a(8) =211a(9) =2311a(10) =2311a(11) =120121a(12) =120121a(13) =120121a(14) =120121a(15) =4084081a(16) =4084081a(17) =106696591a(18) =106696591a(19) =106696591a(20) =106696591a(21) =892371481a(22) =892371481a(23) =892371481a(24) =892371481a(25) =892371481a(26) =892371481a(27) =71166625531a(28) =71166625531a(29) =200560490131
External references
- oeis: A272981