A175249 Noncomposites (A008578) with nonprime (A018252) subscripts.

1, 5, 11, 17, 19, 23, 31, 41, 43, 47, 59, 67, 71, 73, 83, 89, 97, 101, 103, 109, 127, 131, 137, 139, 149, 157, 163, 167, 179, 191, 193, 197, 211, 223, 227, 229, 233, 241, 251, 257, 263, 269, 277, 283, 293, 307, 311, 313, 331, 337, 347, 353, 367, 373, 379, 383, 389, 401, 409, 419

Offset

1,2

Comments

a(n) = noncomposite(nonprime(n)) = A008578(A018252(n)). a(n) U A055003(n) = A008578(n), a(n) U A175248(n+1) = A008578(n) for n >= 1. a(1) = 1, a(n) = noncomposites (A008578) with composite (A002808) subscripts for n >= 2.

Links

Table of n, a(n) for n=1..60.

Example

a(5) = 19 because a(5) = q(b(5)) = q(9) = 19, q = noncomposite, b = nonprime.

Mathematica

Join[ {1}, Table[Prime[Composite(n)-1] , {n, 1, 100}]] (* Terry D. Grant, Aug 16 2016 *).

Crossrefs

Cf. A008578, A018252, A088982.

Sequence in context: A081717 A096264 A239709 * A271982 A338239 A179240

Adjacent sequences: A175246 A175247 A175248 * A175250 A175251 A175252

Keyword

nonn

Author

Jaroslav Krizek, Mar 13 2010

Extensions

a(34)-a(60) from Terry D. Grant, Aug 16 2016

Status

approved