OFFSET

2,1

COMMENTS

a(3) contains three digit composite numbers as every concatenation of two digit numbers n,n+2 and n+3 is == 0 (mod 7).

LINKS

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 138140141.

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 87889091.

EXAMPLE

a(2) = 89 is the concatenation of two successive composite numbers 8 and 9.

a(3) = 138140141 is the concatenation of 138,140 and 141.

CROSSREFS

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Sep 06 2003

EXTENSIONS

More terms from David Wasserman, May 10 2005

STATUS

approved