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A367128
a(1)=a(2)=1; thereafter a(n) is the radius of the sequence's digraph, where jumps from location i to i+-a(i) are permitted (within 1..n-1).
2
1, 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 10, 10, 10, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
OFFSET
1,5
COMMENTS
The radius of the sequence's digraph is the smallest eccentricity of any vertex (location) in the graph. The eccentricity of a location i means the largest number of jumps in the shortest path from location i to any other location.
LINKS
EXAMPLE
To find a(5), we can look at the eccentricity of each location:
i = 1 2 3 4
a(i) = 1, 1, 1, 1
1 <-> 1 <-> 1 <-> 1
eccentricity = 3 2 2 3
i=1 has eccentricity 3 because it requires up to 3 jumps to reach any other location (3 to i=4), and similarly i=4 has eccentricity 3 too.
i=2 and i=3 have eccentricity 2 as they require at most 2 jumps to reach anywhere.
The smallest eccentricity of any location is 2, which makes 2 the radius of the sequence's digraph, so a(5)=2.
PROG
(C) See links.
KEYWORD
nonn
AUTHOR
Neal Gersh Tolunsky, Nov 05 2023
STATUS
approved