

A155492


Concatenation of even n and odd nth nonprime.


0



21, 69, 1015, 1421, 2839, 3245, 4055, 4257, 4663, 4865, 6081, 6891, 7093, 7295, 86115, 88117, 90119, 92121, 94123, 96125, 102133, 104135, 108141, 110143, 112145, 114147, 118153, 120155
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OFFSET

1,1


LINKS



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



EXTENSIONS

Corrected (1421 inserted, 901119 replaced by 90119, 121145 replaced by 112145) R. J. Mathar, May 10 2010


STATUS

approved



