Conjectured values of a(n) defined by: a(n) = first prime appearing in the orbit n, f(n), f(f(n)),...., if it exists; = 0 otherwise, where f(n) = n + sigma(n).

A067579

Conjectured values of a(n) defined by: a(n) = first prime appearing in the orbit n, f(n), f(f(n)),...., if it exists; = 0 otherwise, where f(n) = n + sigma(n).

Terms

    a(0) =2a(1) =2a(2) =3a(3) =11a(4) =5a(5) =137a(6) =7a(7) =23a(8) =0a(9) =0a(10) =11a(11) =0a(12) =13a(13) =269a(14) =479a(15) =47a(16) =17a(17) =137a(18) =19a(19) =61223a(20) =53a(21) =0a(22) =23a(23) =0a(24) =0a(25) =0a(26) =67a(27) =0a(28) =29a(29) =0

External references