A246211 - OEIS

A246211

Self-inverse permutation of natural numbers: a(0) = 0, a(1) = 1, and for n > 1, if A117966(n) < 0, a(n) = A117967(1+a(-(A117966(n)))), otherwise a(n) = A117968(a(A117966(n)-1)).

0, 1, 5, 22, 71, 2, 35, 15, 99, 225, 531, 66, 213, 516, 1899, 7, 73, 172, 307, 127, 1369, 36, 3, 52, 304, 148, 1246, 5408, 17461, 620, 1567, 5321, 41591, 194, 698, 6, 21, 69, 1489, 5165, 16975, 174, 142234, 643, 17287, 587, 695, 173, 5195, 72, 605, 4770, 23, 1761, 12051, 4175, 24134, 389, 137, 431, 3758, 945, 11964, 392, 419, 482, 11, 2872, 104, 37, 3830, 4, 49, 16

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OFFSET

0,3

COMMENTS

This is an instance of entanglement permutation, where complementary pair A117967/A117968 (positive and negative part of inverse of balanced ternary enumeration of integers, respectively) is entangled with the same pair in the opposite order: A117967/A117968, with a(0) set to 0 and a(1) set to 1.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..2187

Indranil Ghosh, Python program to generate the sequence

Index entries for sequences that are permutations of the natural numbers

FORMULA

a(0) = 0, a(1) = 1, and for n > 1, if A117966(n) < 0, a(n) = A117967(1+a(-(A117966(n)))), otherwise a(n) = A117968(a(A117966(n)-1)).

PROG

(Scheme, with memoizing definec-macro from Antti Karttunen's IntSeq-library)

(definec (A246211 n) (cond ((<= n 1) n) ((negative? (A117966 n)) (A117967 (+ 1 (A246211 (- (A117966 n)))))) (else (A117968 (A246211 (- (A117966 n) 1))))))

CROSSREFS

Related or similar permutations: A246207, A246208, A246209, A246210, A004488, A245812, A054429.

Cf. A117966, A117967, A117968.

Sequence in context: A273336 A273768 A032168 * A000345 A011846 A241694

Adjacent sequences: A246208 A246209 A246210 * A246212 A246213 A246214

KEYWORD

nonn

AUTHOR

Antti Karttunen, Aug 19 2014

STATUS

approved