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A286303
The list of x-coordinates for which nonempty columns arise in the set arising from {(1, 0),(2, 0),(0, 1)}, the classical Ulam sequence on the x-axis augmented by a vector in the orthogonal direction.
0
1, 4, 6, 9, 14, 20, 23, 25, 30, 33, 49, 56, 60, 248, 270, 280, 302, 385, 474, 479
OFFSET
1,2
LINKS
Noah Kravitz, Stefan Steinerberger, Ulam Sequences and Ulam Sets, arXiv:1705.01883 [math.CO], 2017.
CROSSREFS
Cf. A002858.
Sequence in context: A310672 A310673 A171664 * A084336 A094750 A241013
KEYWORD
nonn,more
AUTHOR
Michel Marcus, May 05 2017
STATUS
approved