A175250 Nonprimes (A018252) with noncomposite (A008578) subscripts.

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.

Links

Table of n, a(n) for n=1..30.

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

Adjacent sequences: A175247 A175248 A175249 * A175251 A175252 A175253

Keyword

nonn

Author

Jaroslav Krizek, Mar 13 2010

Status

approved