a(n) is the smallest k such that the following are four primes: prime(n)*k-1, prime(n)*k+1, prime(n)*k^2-1, prime(n)*k^2+1. Or -1 if no such k exists.
A266239
a(n) is the smallest k such that the following are four primes: prime(n)*k-1, prime(n)*k+1, prime(n)*k^2-1, prime(n)*k^2+1. Or -1 if no such k exists.
Terms
- a(0) =3a(1) =2a(2) =6a(3) =66a(4) =300a(5) =24a(6) =3744a(7) =27000a(8) =6a(9) =1080a(10) =960a(11) =90a(12) =30a(13) =366a(14) =9204a(15) =8154a(16) =1170a(17) =840a(18) =330a(19) =6090a(20) =84a(21) =27720a(22) =324a(23) =90a(24) =186a(25) =4740a(26) =2856a(27) =6a(28) =24270a(29) =936
External references
- oeis: A266239