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A166985
Primes of the form phi(n)/2.
0
2, 3, 2, 3, 2, 5, 2, 3, 3, 5, 11, 11, 23, 29, 41, 23, 53, 29, 41, 83, 89, 53, 113, 131, 83, 173, 89, 179, 191, 113, 233, 239, 251, 131, 281, 293, 173, 179, 359, 191, 419, 431, 443, 233, 239, 491, 251, 509, 281, 293, 593, 641, 653, 659, 683, 359, 719, 743, 761, 809, 419
OFFSET
1,1
EXAMPLE
a(1)=2 (=phi(5)/2); a(2)=3 (=phi(7)/2); a(3)=2 (=phi(8)/2); a(4)=3 (=phi(9)/2); a(5)=2 (=phi(10)/2); a(6)=5 (=phi(11)/2).
CROSSREFS
Cf. A005384. [From R. J. Mathar, Oct 28 2009]
Sequence in context: A016026 A086757 A369690 * A046215 A256113 A256368
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended by R. J. Mathar, Oct 28 2009
STATUS
approved