A276624 The infinite trunk of ternary beanstalk with reversed subsections.

0, 2, 8, 4, 26, 20, 16, 12, 10, 80, 72, 68, 62, 56, 52, 46, 42, 38, 34, 30, 28, 242, 232, 224, 216, 212, 204, 198, 194, 188, 180, 176, 170, 164, 160, 152, 144, 140, 134, 126, 122, 116, 110, 106, 100, 96, 92, 88, 84, 82, 728, 716, 706, 698, 688, 680, 672, 664, 656, 648, 644, 634, 626, 618, 610, 602, 594, 590, 582, 576, 572

Offset

0,2

Comments

See A276623.

Links

Antti Karttunen, Table of n, a(n) for n = 0..6250

Formula

a(0) = 0; a(1) = 2; for n > 1, if 2*A054861(a(n-1))+1 is not a power of 3, then a(n) = 2*A054861(a(n-1)), otherwise a(n) = A000244(1+A081604(1+2*A054861(a(n-1)))) - 1.

Prog

(Scheme)
(definec (A276624 n) (cond ((zero? n) n) ((= n 1) 2) (else (let ((maybe_next (* 2 (A054861 (A276624 (- n 1)))))) (if (not (= 1 (A053735 (+ 1 maybe_next)))) maybe_next (+ -1 (A000244 (+ 1 (A081604 (+ 1 maybe_next))))))))))

Crossrefs

Cf. A000244, A053735, A054861, A081604, A276623.

Sequence in context: A253884 A054788 A193851 * A193847 A019194 A038214

Adjacent sequences: A276621 A276622 A276623 * A276625 A276626 A276627

Keyword

nonn,base

Author

Antti Karttunen, Sep 11 2016

Status

approved