OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Moebius Function.
EXAMPLE
31 is in the sequence because 31 is a prime and mu(30) = -1.
37 is not in the sequence because, although 37 is prime, mu(36) = 0.
MATHEMATICA
Select[Prime[Range[400]], MoebiusMu[# - 1] == -1 &] (* from T. D. Noe *)
PROG
(PARI) j=[]; forprime(n=1, 2000, if(moebius(n)==moebius(n-1), j=concat(j, n))); j
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Shyam Sunder Gupta, Nov 21 2002
STATUS
approved