OFFSET
0,1
COMMENTS
C1 = 'prevprime(n) followed by n'
C2 = 'n followed by nextprime(n)'
EXAMPLE
n=1551 -> previous prime is 1549, next prime is 1553, thus '15491551' and '15511553' are both primes.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Oct 15 1998
STATUS
approved