OFFSET
1,1
COMMENTS
A262300 is now the main entry for this question.
EXAMPLE
a(8) = 1234567910111213...1873 (ending at 1873, a 6384-digit probable prime, and too large to display here) was found by David Broadhurst on Sep 27 2015.
a(9) = 1234567810111213141516171819,
a(11) = 123456789101213,
and a(19) = 12345678910111213141516171820212223242526272829.
Sep 28, 2015: David Broadhurst has also found a(10), a(12), a(14), a(16), a(17), a(18), and a(20). See A262300 for their values.
a(13) is at present unknown.
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
N. J. A. Sloane and Jerrold B. Tunnell, Sep 25 2015
STATUS
approved