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A061984
a(n) = 1 + a([n/2]) + a([n/3]) with a(0) = 0.
7
0, 1, 2, 3, 4, 4, 6, 6, 7, 8, 8, 8, 11, 11, 11, 11, 12, 12, 15, 15, 15, 15, 15, 15, 19, 19, 19, 20, 20, 20, 20, 20, 21, 21, 21, 21, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 32, 32, 32, 32, 32, 32, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 37, 37, 37, 37, 37, 37, 37, 37, 47
OFFSET
0,3
COMMENTS
If n = 2^a*3^b, then a(n)-a(n-1) = C(a+b, a). - David Wasserman, Nov 17 2005
LINKS
PROG
(Haskell)
a061984 n = a061984_list !! n
a061984_list = 0 : map (+ 1) (zipWith (+)
(map (a061984 . (`div` 2)) [1..]) (map (a061984 . (`div` 3)) [1..]))
-- Reinhard Zumkeller, Jan 11 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Henry Bottomley, May 24 2001
STATUS
approved