A218790 - OEIS

A218790

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 A218782.

1, 3, 5, 13, 21, 37, 53, 117, 181, 309, 437, 693, 949, 1717, 1461, 3509, 5557, 9653, 13749, 21941, 30133, 54709, 46517, 79285, 112053, 210357, 177589, 472501, 308661, 734645, 996789, 2045365, 3093941, 5191093, 7288245, 11482549, 15676853, 28259765, 24065461

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OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..1024

FORMULA

a(n) = A218614(A005187(n)).

PROG

(Scheme with memoization-macro definec): (definec (A218790 n) (cond ((< n 2) n) ((A011371 (* 2 n)) => (lambda (bp) (if (even? bp) (A004754 (A218790 (/ bp 2))) (A004755 (A218790 (/ (-1+ bp) 2))))))))

CROSSREFS

Subset of A218614, i.e. a(n) = A218614(A005187(n)).

Also, a(n) = A054429(A218791(n)). Used to construct A218782, A218783. Cf. also A218787, A218788

Sequence in context: A290441 A222752 A172143 * A168388 A059872 A059873

Adjacent sequences: A218787 A218788 A218789 * A218791 A218792 A218793

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Nov 16 2012

STATUS

approved