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A316995
Sequence of distinct signed integers such that a(1) = 0 and for any n > 0, a(n+1) is of the form a(n) + (-2)^k (where k >= 0) and has the smallest possible absolute value (in case of a tie, minimize k).
2
0, 1, -1, -3, -2, 2, 3, 4, -4, -6, -5, -7, -9, 7, 5, 6, 10, 8, 9, 13, 11, 12, 16, 14, 15, -17, -13, -12, -8, -10, -18, -14, -16, -15, -11, -19, -21, -20, -22, -24, -23, -25, -27, -26, -28, -30, -29, -31, -33, 31, 23, 21, 19, 17, 18, 22, 20, 24, 25, 26, 27, 28
OFFSET
1,4
COMMENTS
This sequence is likely to contain every signed integer.
EXAMPLE
The first terms, alongside the value k such that a(n+1) = a(n) + (-2)^k, are:
n a(n) k
-- ---- --
1 0 0
2 1 1
3 -1 1
4 -3 0
5 -2 2
6 2 0
7 3 0
8 4 3
9 -4 1
10 -6 0
11 -5 1
12 -7 1
13 -9 4
14 7 1
15 5 0
16 6 2
17 10 1
18 8 0
19 9 2
20 13 1
PROG
(PARI) See Links section.
CROSSREFS
Cf. A122803.
Sequence in context: A046822 A129001 A029246 * A338241 A222456 A222673
KEYWORD
sign
AUTHOR
Rémy Sigrist, Jul 18 2018
STATUS
approved