a(n) = number of primes of the form k^n - m^k where k > m > 0.

Terms

a(0) =0a(1) =1a(2) =2a(3) =6a(4) =7a(5) =2a(6) =14a(7) =7a(8) =11a(9) =10a(10) =33a(11) =10a(12) =42a(13) =35a(14) =47a(15) =39a(16) =122a(17) =22a(18) =248a(19) =113a(20) =247a(21) =236a(22) =751a(23) =75a(24) =1268a(25) =812a(26) =1422a(27) =1531a(28) =4543a(29) =87