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A285760
a(n) = a(n - 2 - a(n - 1)) + a(n - 2 - a(n - 4)), with a(1) = 1, a(2) = 1, a(3) = 2, a(4) = 2.
6
1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 5, 5, 6, 7, 7, 7, 8, 8, 8, 9, 9, 10, 11, 11, 12, 12, 13, 13, 14, 14, 14, 15, 15, 16, 16, 16, 17, 17, 18, 19, 19, 20, 20, 21, 21, 22, 23, 23, 23, 24, 24, 25, 25, 26, 27, 27, 27, 28, 28, 28, 29, 29, 30, 31, 31
OFFSET
1,3
COMMENTS
The sequence a(n) is monotonic, with successive terms increasing by 0 or 1. So the sequence hits every positive integer.
LINKS
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
A285760:=proc(n) option remember: if n <= 0 then 0: elif n = 1 then 1: elif n = 2 then 1: elif n = 3 then 2: elif n = 4 then 2: else A285760(n-2-A285760(n-1)) + A285760(n-2-A285760(n-4)): fi: end:
KEYWORD
nonn
AUTHOR
Nathan Fox, Apr 25 2017
STATUS
approved