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A175250
Nonprimes (A018252) with noncomposite (A008578) subscripts.
2
1, 4, 6, 9, 12, 18, 21, 26, 28, 34, 42, 45, 52, 57, 60, 65, 74, 81, 84, 91, 95, 98, 106, 112, 119, 128, 133, 135, 141, 143
OFFSET
1,2
COMMENTS
a(n) = nonprime(noncomposite(n)) = A018252(A008578(n)). a(n) U A102615(n+1) = A018252(n) for n >= 1. a(1) = 1, a(n) = A078782(n-1) = nonprimes (A008578) with prime (A000040) subscripts for n >=2.
EXAMPLE
a(5) = 12 because a(5) = b(q(5)) = b(7) = 12, q = noncomposite, b = nonprime.
CROSSREFS
Sequence in context: A310669 A310670 A088765 * A078782 A165897 A020165
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Mar 13 2010
STATUS
approved