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 A285727 a(1) = a(2) = 0, and for n > 2, a(n) = A252463(A252463(n)). 4
 0, 0, 1, 1, 2, 2, 3, 2, 2, 3, 5, 3, 7, 5, 3, 4, 11, 4, 13, 5, 5, 7, 17, 6, 4, 11, 4, 7, 19, 6, 23, 8, 7, 13, 6, 9, 29, 17, 11, 10, 31, 10, 37, 11, 6, 19, 41, 12, 9, 9, 13, 13, 43, 8, 10, 14, 17, 23, 47, 15, 53, 29, 10, 16, 14, 14, 59, 17, 19, 15, 61, 18, 67, 31, 9, 19, 15, 22, 71, 20, 8, 37, 73, 21, 22, 41, 23, 22, 79, 12, 21, 23, 29, 43, 26, 24, 83, 25, 14 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS For n >= 3, a(n) gives the contents of the grandparent node of the node containing n in binary trees like A005940 and A163511. Each number larger than one occurs exactly four times in this sequence. LINKS Antti Karttunen, Table of n, a(n) for n = 1..8192 FORMULA a(1) = a(2) = 0, and for n > 2, a(n) = A252463(A252463(n)). For n > 2, if n is even, a(n) = A252463(n/2), otherwise a(n) = A252463(A064989(n)). PROG (Scheme) (define (A285727 n) (if (<= n 2) 0 (A252463 (A252463 n)))) CROSSREFS Cf. A005940, A064989, A163511, A252463, A285728. Sequence in context: A258568 A108939 A138143 * A281908 A106441 A131836 Adjacent sequences:  A285724 A285725 A285726 * A285728 A285729 A285730 KEYWORD nonn AUTHOR Antti Karttunen, Apr 25 2017 STATUS approved

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Last modified May 23 05:25 EDT 2019. Contains 323508 sequences. (Running on oeis4.)