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A303577
Break up the list of values of the divisor function d(k) into nondecreasing runs; sequence gives lengths of successive runs.
3
4, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 4, 4, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 1, 1, 2, 4, 2, 2, 4, 4, 2, 3, 1, 2, 2, 2, 2, 3, 3, 4, 2, 2, 2, 2, 4, 2, 2, 4, 4, 2, 2, 2, 2, 4, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 4, 2, 2, 4, 4, 2, 2, 4, 4, 2, 2, 1, 1, 2, 4, 2, 2, 2, 2, 6
OFFSET
1,1
LINKS
EXAMPLE
The initial values of d(k) = A000005(k) for k = 1,2,3,... are
1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 9, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 10, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 12, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 12, 2, 4, 6, 6, 4, 8, 2, ...
Breaking this up into nondecreasing runs we get:
[1, 2, 2, 3], [2, 4], [2, 4], [3, 4], [2, 6], [2, 4, 4, 5], [2, 6], [2, 6], [4, 4], [2, 8], [3, 4, 4, 6], [2, 8], [2, 6], [4, 4, 4, 9], [2, 4, 4, 8], [2, 8], [2, 6, 6], [4], [2, 10], [3, 6], [4, 6], [2, 8], [4, 8], [4, 4], [2, 12], [2, 4, 6, 7], ...
whose successive lengths are
4,2,2,2,2,4,2,2,2,2,4,2,2,4,4,2,3,1,2,...
CROSSREFS
Cf. A000005.
A303578(m) gives value of n that starts the m-th run.
A284597(m) is the smallest number that starts a run of length m.
Sequence in context: A280135 A297825 A338150 * A010314 A080133 A054575
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 29 2018
EXTENSIONS
More terms from Seiichi Manyama, Apr 29 2018
STATUS
approved