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A338249
Nonpositive values in A053985, in order of appearance and negated.
2
0, 2, 1, 8, 7, 10, 9, 4, 3, 6, 5, 32, 31, 34, 33, 28, 27, 30, 29, 40, 39, 42, 41, 36, 35, 38, 37, 16, 15, 18, 17, 12, 11, 14, 13, 24, 23, 26, 25, 20, 19, 22, 21, 128, 127, 130, 129, 124, 123, 126, 125, 136, 135, 138, 137, 132, 131, 134, 133, 112, 111, 114, 113
OFFSET
0,2
COMMENTS
This sequence is a self-inverse permutation of the nonnegative integers (the offset has been set to 0 so as to get a permutation).
There is only one fixed point: a(0) = 0.
FORMULA
a(n) = -A053985(A053754(n+1)) for any n >= 0.
EXAMPLE
A053985 = 0, 1, -2, -1, 4, 5, 2, 3, -8, -7, -10, -9, -4, -3, -6, -5, ...
We keep: 0, 2, 1, 8, 7, 10, 9, 4, 3, 6, 5, ...
PROG
(PARI) A053985(n) = fromdigits(binary(n), -2)
print (-select(v -> v<=0, apply(A053985, [0..147])))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Oct 18 2020
STATUS
approved