Intersection of A068017 and A068019: numbers n such that both sigma(n) and phi(n) are middle terms between (different) twin prime pairs.
A071348
Intersection of A068017 and A068019: numbers n such that both sigma(n) and phi(n) are middle terms between (different) twin prime pairs.
Terms
- a(0) =10a(1) =26a(2) =38a(3) =135a(4) =206a(5) =209a(6) =216a(7) =278a(8) =371a(9) =398a(10) =416a(11) =545a(12) =560a(13) =650a(14) =698a(15) =792a(16) =866a(17) =924a(18) =1062a(19) =1125a(20) =1286a(21) =1364a(22) =1403a(23) =1482a(24) =1512a(25) =1946a(26) =2021a(27) =2151a(28) =2306a(29) =2432
External references
- oeis: A071348