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 A285763 a(n) = a(a(n - 2)) + a(n - a(n - 2)), with a(1) = 1, a(2) = a(3) = a(4) = 2, a(5) = 3. 2
 1, 2, 2, 2, 3, 4, 4, 4, 5, 6, 7, 8, 8, 8, 8, 8, 9, 10, 11, 12, 13, 14, 14, 14, 15, 16, 16, 16, 16, 16, 16, 16, 17, 18, 19, 20, 21, 22, 23, 24, 24, 24, 25, 26, 27, 28, 28, 28, 29, 30, 30, 30, 30, 30, 31, 32, 32, 32, 32, 32, 32, 32, 32, 32 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The sequence a(n) is monotonic, with successive terms increasing by 0 or 1. So the sequence hits every positive integer. This sequence can be obtained from the Hofstadter-Conway sequence A004001 using a construction of Isgur et al. LINKS Nathan Fox, Table of n, a(n) for n = 1..10000 A. Isgur, R. Lech, S. Moore, S. Tanny, Y. Verberne, and Y. Zhang, Constructing New Families of Nested Recursions with Slow Solutions, SIAM J. Discrete Math., 30(2), 2016, 1128-1147. (20 pages); DOI:10.1137/15M1040505 MAPLE A285763:=proc(n) option remember: if n <= 0 then 0: elif n = 1 then 1: elif n = 2 then 2: elif n = 3 then 2: elif n = 4 then 2: elif n = 5 then 3: else A285763(A285763(n-2)) + A285763(n-A285763(n-2)): fi: end: MATHEMATICA a = 1; a = a = a = 2; a = 3; a[n_] := a[n] = a[a[n - 2]] + a[n - a[n - 2]]; Array[a, 64] (* Michael De Vlieger, Apr 26 2017 *) CROSSREFS Cf. A004001, A285764. Sequence in context: A126257 A025773 A308303 * A294621 A029077 A112176 Adjacent sequences:  A285760 A285761 A285762 * A285764 A285765 A285766 KEYWORD nonn AUTHOR Nathan Fox, Apr 25 2017 STATUS approved

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Last modified October 18 11:19 EDT 2021. Contains 348067 sequences. (Running on oeis4.)