OFFSET
1,2
EXAMPLE
a(5) = a(4) + a(4 - the number of odd terms so far) = a(4) + a(4-3) = 5 + 1 = 6.
MATHEMATICA
a[ 1 ] = 1; a[ 2 ] = 2; a[ n_ ] := a[ n ] = Block[ {e = 0}, Do[ If[ EvenQ[ a[ k ] ], e++ ], {k, 1, n - 1} ]; If[ EvenQ[ n ], a[ n - 1 ] + a[ n - 1 - e ], a[ n - 1 ] + a[ e ] ] ]; Table[ a[ n ], {n, 1, 15} ]
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Apr 21 2001
STATUS
approved