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A338245
Nonnegative values in A117966, in order of appearance.
5
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
0,3
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.
FORMULA
a(0) = 0.
a(n) = A117966(A132141(n)) for any n > 0.
EXAMPLE
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, ...
PROG
(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])))
CROSSREFS
See A338248 for a similar sequence.
Sequence in context: A091477 A075593 A145421 * A352417 A286681 A019474
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Oct 18 2020
STATUS
approved