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 A007731 a(n) = a(floor(n/2)) + a(floor(n/3)) + a(floor(n/6)). 8
 1, 3, 5, 7, 9, 9, 15, 15, 17, 19, 19, 19, 29, 29, 29, 29, 31, 31, 41, 41, 41, 41, 41, 41, 55, 55, 55, 57, 57, 57, 57, 57, 59, 59, 59, 59, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 103, 103, 103, 103, 103, 103, 117, 117 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS T. D. Noe, Table of n, a(n) for n = 0..10000 P. Erdős, A. Hildebrand, A. Odlyzko, P. Pudaite and B. Reznick, The asymptotic behavior of a family of sequences, Pacific J. Math., 126 (1987), pp. 227-241. FORMULA From given link, a(n) is asymptotic to c*n where c = 12/log(432) = 1.97744865... - Benoit Cloitre, Dec 18 2002 MAPLE A007731 := proc(n) option remember; if n=0 then RETURN(1) else RETURN( A007731(trunc(n/2))+A007731(trunc(n/3))+A007731(trunc(n/6))); fi; end; MATHEMATICA a[n_] := a[n] = a[Floor[n/2]] + a[Floor[n/3]] + a[Floor[n/6]] ; a[0] = 1; Table[a[n], {n, 0, 60}] (* Jean-François Alcover, Mar 06 2014 *) PROG (Haskell) a007731 n = a007731_list !! n a007731_list = 1 : (zipWith3 (\u v w -> u + v + w)    (map (a007731 . (`div` 2)) [1..])    (map (a007731 . (`div` 3)) [1..])    (map (a007731 . (`div` 6)) [1..])) -- Reinhard Zumkeller, Jan 11 2014 (PARI) a(n)=if(n<5, 2*n+1, a(n\2) + a(n\3) + a(n\6)) \\ Charles R Greathouse IV, Feb 08 2017 CROSSREFS Cf. A083662, A088468, A165704, A165706, A061984. Sequence in context: A217250 A213923 A218452 * A306590 A249494 A079377 Adjacent sequences:  A007728 A007729 A007730 * A007732 A007733 A007734 KEYWORD nonn,easy,nice AUTHOR STATUS approved

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Last modified October 15 10:15 EDT 2019. Contains 328026 sequences. (Running on oeis4.)