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 A218791 a(n) = binary code (shown here in decimal) of the position of the predecessor of the natural number pair (2n,2n+1) in the compact beanstalk-tree A218780. 4
 1, 2, 6, 10, 26, 58, 42, 74, 202, 458, 330, 842, 586, 1354, 1610, 2634, 6730, 14922, 10826, 27210, 19018, 43594, 51786, 117322, 84554, 182858, 215626, 313930, 477770, 838218, 576074, 1100362, 3197514, 7391818, 5294666, 13683274, 9488970, 22071882, 26266186 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS A. Karttunen, Table of n, a(n) for n = 1..1024 FORMULA a(n) = A218615(A005187(n)). PROG (Scheme with memoization-macro definec): (definec (A218791 n) (cond ((< n 2) n) ((A011371 (* 2 n)) => (lambda (bp) (if (odd? bp) (A004754 (A218791 (/ (-1+ bp) 2))) (A004755 (A218791 (/ bp 2)))))))) CROSSREFS Subset of A218615, i.e., a(n) = A218615(A005187(n)). Also, a(n) = A054429(A218790(n)). (Note also how the first five or so terms are twice the terms in the beginning of A218790, shifted by one term.) Used to construct A218780, A218781. Cf. also A218787, A218788. Sequence in context: A217381 A162581 A061547 * A320429 A319014 A190034 Adjacent sequences:  A218788 A218789 A218790 * A218792 A218793 A218794 KEYWORD nonn,base AUTHOR Antti Karttunen, Nov 16 2012 STATUS approved

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Last modified December 14 09:41 EST 2019. Contains 329979 sequences. (Running on oeis4.)