OFFSET
1,1
COMMENTS
Maple worksheet available upon request. Here is the sequence of minimal composites in base 12, where X is 10 and E is 11. 4, 6, 8, 9, X, 10, 12, 13, 20, 21, 22, 23, 2E, 30, 32, 33, 50, 52, 53, 55, 70, 71, 72, 73, 77, 7E, E0, E1, E2, E3, EE, 115, 151, 15E, 257, 275, 311, 317, 31E, 351, E57, E75, 1111, 1117, 111E, 5111.
EXAMPLE
a(13)=35=2E since no earlier composite is of the form "*2*E*". The list of minimal composites can be constructed using a sieve-like process: subsequently eliminate from the list of composites all composites of the form "*2*E*". Assuming all previous terms have been similarly determined, then the next remaining composite should be 30.
CROSSREFS
KEYWORD
nonn
AUTHOR
Walter Kehowski, Sep 14 2005; name corrected Sep 18 2005
STATUS
approved