OFFSET
0,4
COMMENTS
We could have instead taken k over the distinct positive values of the substrings in binary n, and get the same sequence, since a(0)=0.
EXAMPLE
9 in binary is 1001. The distinct nonnegative integers that occur as substrings in binary 9 are 0, 1, 2 (10 in binary), 4 (100 in binary), and 9 (1001 in binary). And 9 = a(0) + a(1) + a(2) + a(4) + a(9) = 0 + 1 + 1 + 2 + 5.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Sep 17 2009
EXTENSIONS
Extended by Ray Chandler, Mar 13 2010
STATUS
approved