OFFSET
2,3
EXAMPLE
The 8 powers with unique digits in base 5 are 1, 4, 8, 9, 16, 27, 144, and 576; in base 5 these are 1, 4, 13, 14, 31, 102, 1304, and 4301.
PROG
(PARI) okdigs(digs) = {for (i = 1, #digs-1, for (j = i+1, #digs, if (digs[j] == digs[i], return (0); ); ); ); return (1); }
a(n) = {b = n; sols = Set([1]); vmax = b^b; pmax = ceil(log(vmax)/log(2)); for (p = 2, pmax, i = 2; while ((iep = i^p) < vmax, if (okdigs(digits(iep, b)), sols = Set(concat(sols, iep)); ); i++; ); ); #sols; } \\ Michel Marcus, Aug 19 2013
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Johan Särnbratt, Apr 04 2009
EXTENSIONS
a(11) - a(16) from Johan Särnbratt, Apr 21 2009
STATUS
approved