A338245 Nonnegative values in A117966, in order of appearance.

0, 1, 3, 4, 2, 9, 10, 8, 12, 13, 11, 6, 7, 5, 27, 28, 26, 30, 31, 29, 24, 25, 23, 36, 37, 35, 39, 40, 38, 33, 34, 32, 18, 19, 17, 21, 22, 20, 15, 16, 14, 81, 82, 80, 84, 85, 83, 78, 79, 77, 90, 91, 89, 93, 94, 92, 87, 88, 86, 72, 73, 71, 75, 76, 74, 69, 70, 68

Offset: 0

Author

Rémy Sigrist, Oct 18 2020

Keywords

• nonn
• base

Comments

This sequence is a permutation of the nonnegative integers with inverse A338247 (the offset has been set to 0 so as to get a permutation).

There are only two fixed points: a(0) = 0 and a(1) = 1.

Examples

			A117966 = 0, 1, -1, 3, 4, 2, -3, -2, -4, 9, 10, 8, 12, 13, 11, 6, 7, 5, ...
We keep:  0, 1,     3, 4, 2,             9, 10, 8, 12, 13, 11, 6, 7, 5, ...
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..9841
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

See A338248 for a similar sequence.

Cf. A117966, A132141, A338246, A338247.

Programs

PARI

A117966(n) = subst(Pol(apply(x->if(x == 2, -1, x), digits(n, 3)), 'x), 'x, 3)
print (select(v -> v>=0, apply(A117966, [0..107])))

Formula

a(0) = 0.

a(n) = A117966(A132141(n)) for any n > 0.