

A140366


a(n) = isprime(6n1) + 2*isprime(6n5), where isprime = A010051.


0



1, 3, 3, 3, 1, 2, 3, 3, 1, 1, 2, 3, 2, 3, 1, 0, 3, 3, 3, 0, 0, 3, 1, 2, 1, 2, 2, 3, 1, 1, 2, 1, 3, 2, 0, 2, 0, 3, 3, 1, 2, 1, 1, 1, 1, 2, 3, 2, 1, 0, 0, 3, 3, 0, 0, 2, 2, 1, 3, 1
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OFFSET

1,2


COMMENTS

The idea is to consider 2bit words, where the least resp. most significant bit correspond to primality of the respective member in the couple (6n1,6n5). (It might have been more natural to inverse the correspondences, i.e. to associate the LSB to the smaller number of the pair.)  M. F. Hasler, Jun 16 2008


LINKS



PROG

(PARI) a(n)=isprime(6*n5)<<1+isprime(6*n1) \\ M. F. Hasler, Jun 16 2008


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



