OFFSET
1,2
COMMENTS
EXAMPLE
For k=1, 16-1 is 15 with sum of digits 6, so 1 is a term.
For k=2, 16^2-1 is 255 with sum of digits 12, so 2 is a term.
MATHEMATICA
Select[Range[250], 6#==Total[IntegerDigits[16^#-1]]&] (* Harvey P. Dale, Nov 13 2012 *)
PROG
(PARI) is(n) = 6*n == sumdigits(16^n-1) \\ Iain Fox, Nov 24 2017
CROSSREFS
KEYWORD
base,more,nonn
AUTHOR
Max Alekseyev, Sep 24 2009
STATUS
approved