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A156242
Bisection of A054353.
6
3, 6, 9, 12, 15, 19, 21, 24, 27, 30, 33, 36, 39, 42, 45, 47, 50, 54, 57, 60, 63, 66, 69, 72, 75, 77, 81, 84, 87, 90, 93, 96, 100, 102, 105, 108, 111, 114, 117, 120, 123, 127, 129, 132, 136, 139, 142, 145, 147, 151, 154, 156, 159, 163, 166, 169, 172, 174, 177, 181
OFFSET
1,1
COMMENTS
Positions of strict descents in the Kolakoski sequence A000002. Strict ascents are A156243. - Gus Wiseman, Mar 31 2020
FORMULA
a(n) = A054353(2n).
A000002(a(n))=2 and A000002(a(n)+1)=1. - Jon Perry, Sep 04 2012
MATHEMATICA
kolagrow[q_]:=If[Length[q]<2, Take[{1, 2}, Length[q]+1], Append[q, Switch[{q[[Length[Split[q]]]], q[[-2]], Last[q]}, {1, 1, 1}, 0, {1, 1, 2}, 1, {1, 2, 1}, 2, {1, 2, 2}, 0, {2, 1, 1}, 2, {2, 1, 2}, 2, {2, 2, 1}, 1, {2, 2, 2}, 1]]]
kol[n_Integer]:=Nest[kolagrow, {1}, n-1];
Join@@Position[Partition[kol[100], 2, 1], {2, 1}] (* Gus Wiseman, Mar 31 2020 *)
CROSSREFS
The version for prime gaps is A258026.
Sizes of maximal weakly increasing subsequences of A000002 are A332875.
Sequence in context: A039004 A070021 A083354 * A060293 A336803 A220657
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 07 2009
STATUS
approved