A089601 Interleaving of A089591 and A089600.

0, 0, 1, 1, 2, 10, 11, 11, 12, 20, 21, 101, 102, 110, 111, 111, 112, 120, 121, 201, 202, 210, 211, 1011, 1012, 1020, 1021, 1101, 1102, 1110, 1111, 1111, 1112, 1120, 1121, 1201, 1202, 1210, 1211, 2011, 2012, 2020, 2021, 2101, 2102, 2110, 2111, 10111

Offset

0,5

Links

Table of n, a(n) for n=0..47.

Formula

To get a(n), drop last digit from either A089591(n) or A089600(n+1).

Maple

A089591 := proc(n) option remember ; local nhalf ; if n <= 1 then RETURN(n) ; else nhalf := floor(n/2) ; if n mod 2 = 1 then RETURN(10*A089591(nhalf) +1) ; else RETURN(10*(A089591(nhalf-1)+1)) ; fi ; fi ; end: A089600 := proc(n) option remember ; local nhalf ; nhalf := floor(n/2) ; if n <= 1 then RETURN(n) ; else if n mod 2 = 1 then RETURN(10*A089600(nhalf) +1) ; else RETURN(10*A089591(nhalf-1)+2) ; fi ; fi ; end: A089601 := proc(n) if n mod 2 = 0 then A089600(n/2) ; else A089591((n-1)/2) ; fi ; end: seq(A089601(n), n=0..80) ; # R. J. Mathar, Jul 20 2007

Crossrefs

Cf. A089591, A089600.

Sequence in context: A222638 A299982 A367638 * A171893 A278816 A043072

Adjacent sequences: A089598 A089599 A089600 * A089602 A089603 A089604

Keyword

nonn,easy,base

Author

Jeff Erickson, Dec 31 2003

Extensions

More terms from R. J. Mathar, Jul 20 2007

Status

approved