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A061984 a(n) = 1 + a([n/2]) + a([n/3]) with a(0) = 0. 7

%I #7 Jan 11 2014 18:05:55

%S 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,

%T 20,20,20,20,20,21,21,21,21,27,27,27,27,27,27,27,27,27,27,27,27,32,32,

%U 32,32,32,32,36,36,36,36,36,36,36,36,36,36,37,37,37,37,37,37,37,37,47

%N a(n) = 1 + a([n/2]) + a([n/3]) with a(0) = 0.

%C If n = 2^a*3^b, then a(n)-a(n-1) = C(a+b, a). - _David Wasserman_, Nov 17 2005

%H Reinhard Zumkeller, <a href="/A061984/b061984.txt">Table of n, a(n) for n = 0..10000</a>

%o (Haskell)

%o a061984 n = a061984_list !! n

%o a061984_list = 0 : map (+ 1) (zipWith (+)

%o (map (a061984 . (`div` 2)) [1..]) (map (a061984 . (`div` 3)) [1..]))

%o -- _Reinhard Zumkeller_, Jan 11 2014

%Y Cf. A061980, A061985, A061986, A061987.

%Y Cf. A007731.

%K nonn

%O 0,3

%A _Henry Bottomley_, May 24 2001

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Last modified April 25 12:53 EDT 2024. Contains 371969 sequences. (Running on oeis4.)