OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1900
PROG
(PARI) {m=400000000; a=0; g=0; e=0; p=2; q=3; r=5; while(r<=m, if((p+r)/2==q, if(a>0, b=(a+q)/2; if(isprime(b), if(g>0, h=(g+b)/2; if(isprime(h), if(e>0, f=(e+h)/2; if(isprime(f), print1(f, ", "))); e=h)); g=b)); a=q); p=q; q=r; r=nextprime(r+1))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Jan 11 2007
STATUS
approved