OFFSET
1,2
MATHEMATICA
Table[FromDigits[Flatten[IntegerDigits[n, 2]/.{0->{0, 0, 0, 0}}]], {n, 20}] (* Harvey P. Dale, Feb 19 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 27 2003
STATUS
approved