OFFSET
1,1
COMMENTS
Sequence A167500 starts 1,2,4,7,... = 1,10,100,111,.... when written in binary (A167502). This sequence lists the bits one by one, MSB first: 1,1,0,1,0,0,1,1,1,...; by definition A167500 lists the nonzero terms of this function, and reciprocally this sequence is the characteristic function of A167500.
PROG
(PARI) a=b=[]; for(n=1, 30, #b >= n & for( i=a[n-1]+1, #b, b[i] & (a=concat(a, i)) & break); #a<n & a=concat(a, #b+1); b=concat(b, binary( a[n] ))); b
CROSSREFS
KEYWORD
base,nonn
AUTHOR
M. F. Hasler, Nov 05 2009
STATUS
approved