OFFSET
1,2
COMMENTS
Definition requires "length > 2" because all numbers n > 2 are trivially represented as "11" in base n-1.
0 included at the suggestion of Franklin T. Adams-Watters (and others) as 0 = 000 in any base.
LINKS
Vojtech Strnad, Table of n, a(n) for n = 1..10000
Wolfram Demonstrations Project, Mixed Radix Number Representations [From Daniel Forgues, Nov 13 2009]
EXAMPLE
26 is a term because 26_10 = 222_3.
PROG
(PARI) digits(n, b) = if(n<b, [n], concat(digits(floor(n/b), b), n%b))
is_repdigit(d) = {local(a, r); r=1; a=d[1]; for(i=2, matsize(d)[2], if(a!=d[i], r=0)); r}
for(n=1, 1200, b=2; while(n>=b^2+b+1, d=digits(n, b); if(is_repdigit(d), print(n, " = ", d, " base ", b)); b++)) \\ Michael B. Porter
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Andrew Weimholt, Nov 12 2009
STATUS
approved