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A293773
Let P be the sequence of distinct lattice points defined by the following rules: P(1) = (0,0), P(2) = (1,0), and for any i < j < k, P(k) does not lie on the vector (P(i), P(j)), and for any n > 2, P(n) is the closest lattice point to P(n-1) such that the angle of the vectors (P(n-2), P(n-1)) and (P(n-1), P(n)), say t, satisfies 0 < t <= Pi/2, and in case of a tie, minimize the angle t; a(n) = Y-coordinate of P(n).
2
0, 0, 1, 1, 0, -1, -1, 0, 1, 2, 2, 1, -1, -2, -2, -1, 1, 2, 3, 3, 2, 1, -1, -2, -3, -3, -2, -1, 2, 3, 4, 4, 3, 1, 0, -1, -3, -4, -4, -3, -2, 0, 4, 5, 5, 4, 2, -1, -2, -3, -5, -5, -4, -1, 1, 4, 5, 6, 6, 5, 3, 2, -2, -3, -4, -5, -6, -6, -5, -3, 0, 6, 7, 7, 6, 4
OFFSET
1,10
COMMENTS
See A293772 for the corresponding X-coordinates and additional comments.
CROSSREFS
Cf. A293772.
Sequence in context: A298600 A292470 A293681 * A071017 A112049 A055230
KEYWORD
sign,look
AUTHOR
Rémy Sigrist, Oct 16 2017
STATUS
approved