OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
E.g. 5*7=17+19-1,11*13=71+73-1.
PROG
(PARI) list(lim)=my(v=List(), p=3, r); forprime(q=5, lim, if(q-p==2 && isprime(r=p*q\2) && isprime(r+2), listput(v, q)); p=q); Vec(v) \\ Charles R Greathouse IV, Sep 29 2015
(PARI) is(n)=isprime(n) && isprime(n-2) && isprime(n*(n-2)\2) && isprime(n*(n-2)\2+2) \\ Charles R Greathouse IV, Sep 29 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved