OFFSET
1,1
COMMENTS
Previous name: Primes produced in A053184.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1200
MATHEMATICA
Select[#^2 + # - 1 &/@Prime[Range[200]], PrimeQ] (* Vincenzo Librandi, Aug 12 2017 *)
PROG
(PARI) isA053185(n)={local(r); r=0; for(i=floor(sqrt(n+1)), ceil(sqrt(n)-1), if(isprime(i) && n==i^2+i-1 && isprime(n), r=1)); r} \\ Michael B. Porter, May 10 2010
(PARI) lista(nn) = forprime(p=2, nn, if (isprime(q=p^2+p-1), print1(q, ", "))); \\ Michel Marcus, Aug 12 2017
(Magma) [p: p in PrimesUpTo(600) | IsPrime(p) where p is p^2+p-1]; // Vincenzo Librandi, Aug 12 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Mar 01 2000
EXTENSIONS
New name from Michel Marcus, Aug 12 2017
STATUS
approved