login
A333866
Lexicographically earliest sequence of distinct positive integers, which when mapped onto a square spiral, gives a set without four distinct points forming a square.
2
1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 17, 18, 20, 21, 26, 27, 30, 31, 37, 38, 41, 43, 44, 46, 50, 52, 55, 57, 58, 65, 66, 70, 73, 79, 82, 83, 88, 91, 92, 101, 102, 104, 110, 111, 116, 122, 124, 127, 132, 133, 141, 143, 145, 146, 152, 156, 157, 167, 170, 171, 180
OFFSET
1,2
COMMENTS
This sequence has similarities with A005282.
EXAMPLE
The first terms, mapped onto a square spiral, are:
65---*---*---*---*---*---*--58--57
| |
66 37---*---*---*---*---*--31 *
| | | |
* 38 17---*---*--14--13 30 55
| | | | | |
* * 18 5---*---3 * * * <-- As the sequence contains 2, 13
| | | | | | | | and 27, it cannot contain 54.
* * * 6 1---2 11 * *
| | | | | | |
70 41 20 7---*---*--10 27 52
| | | | |
* * 21---*---*---*---*--26 *
| | |
* 43--44---*--46---*---*---*--50
|
73---*---*---*---*---*--79---*---*
PROG
(C#) See Links section.
CROSSREFS
See A333825 for a similar sequences.
Sequence in context: A235991 A377871 A327906 * A325362 A339563 A325396
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Apr 08 2020
STATUS
approved