OFFSET
1,3
MAPLE
for n from 1 to 100 do p := ithprime(ithprime(n))-2*n ; if not isprime(p) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Jan 18 2009
MATHEMATICA
Select[Table[Prime[Prime[n]] - 2 n, {n, 80}], ! PrimeQ[#] &] (* Vincenzo Librandi, Jan 08 2019 *)
PROG
(Magma) [a: n in [1..100] | not IsPrime(a) where a is NthPrime(NthPrime(n)) -2*n]; // Vincenzo Librandi, Jan 08 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jan 16 2009
EXTENSIONS
35 replaced with 45 and 645 replaced with 675 by R. J. Mathar, Jan 18 2009
STATUS
approved