OFFSET
1,1
EXAMPLE
Since n=2=even and nonprime(2)=1=odd, concatenate 21 = a(1). Since n=6=even and nonprime(6)=9=odd, concatenate 69 = a(2). Since n=10=even and nonprime(10)=15=odd, concatenate 1015 = a(3), etc.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Juri-Stepan Gerasimov, Jan 23 2009
EXTENSIONS
Corrected (1421 inserted, 901119 replaced by 90119, 121145 replaced by 112145) R. J. Mathar, May 10 2010
Edited by N. J. A. Sloane, May 15 2010
STATUS
approved