A175248 Noncomposites (A008578) with noncomposite (A008578) subscripts.

1, 2, 3, 7, 13, 29, 37, 53, 61, 79, 107, 113, 151, 173, 181, 199, 239, 271, 281, 317, 349, 359, 397, 421, 457, 503, 541, 557, 577, 593, 613, 701, 733, 769, 787, 857, 863, 911, 953, 983, 1021, 1061, 1069, 1151, 1163, 1193, 1213, 1291, 1399, 1429, 1439, 1459

Offset: 1

Author

Jaroslav Krizek, Mar 13 2010

Keywords

• nonn

Comments

Noncomposite numbers of order 2.

a(n) = noncomposite(noncomposite(n)) = A008578(A008578(n)). a(1) = 1, a(n) = A055003(n) for n >=2. a(n) U A175249(n+1) = A008578 for n >= 1.

Examples

			a(5) = 13 because a(5) = q(q(5)) = q(7) = 13, q = noncomposite.
		

Crossrefs

Cf. A006450, A102615.

Formula

a(n)=A008578(A008578(n)).

Extensions

More terms from Juri-Stepan Gerasimov, Apr 15 2010

Edited by N. J. A. Sloane, Apr 21 2010 at the suggestion of R. J. Mathar