OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Wall-Sun-Sun Prime
PROG
(PARI) a(n) = my(p=prime(n)); 2*kronecker(p, 5) % p^2; \\ Michel Marcus, Aug 03 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Nov 03 2005
STATUS
approved