A338249 Nonpositive values in A053985, in order of appearance and negated.

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.

Links

Rémy Sigrist, Table of n, a(n) for n = 0..10922

Index entries for sequences that are permutations of the natural numbers

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

Cf. A053754, A053985, A338248.

Sequence in context: A248052 A340629 A105672 * A214271 A372474 A262007

Adjacent sequences: A338246 A338247 A338248 * A338250 A338251 A338252

Keyword

nonn,base

Author

Rémy Sigrist, Oct 18 2020

Status

approved