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A101620 Decimal encoding of digraph topologies. 0
1, 3, 9, 11, 13, 15, 129, 131, 133, 137, 139, 141, 143, 145, 153, 161, 163, 165, 171, 175, 177, 179, 187, 193, 195, 197, 205, 207, 209, 213, 221, 241, 243, 245, 255 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The sequence encodes labeled digraph topologies as described by and counted in A000798.
LINKS
EXAMPLE
Let a = 2, b = 4, c = 16, d = 256, ...
a(19) = 171 because we can map { }, a, ab, ac, abc to 1 + 2 + 8 + 32 + 128
Viewed as an array the table begins
1
3
9 11 13 15
129 131 133 137 139 141 143 145 153 161 163 165 171 175 177 ...
with respectively 1 1 4 29 355 ... (A000798) entries on each row.
CROSSREFS
Sequence in context: A074261 A059868 A101735 * A235583 A287333 A174813
KEYWORD
more,nonn,tabf,base
AUTHOR
Alford Arnold, Dec 10 2004
STATUS
approved

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Last modified March 28 05:02 EDT 2024. Contains 371235 sequences. (Running on oeis4.)