OFFSET
1,5
COMMENTS
This is a variation of A335780 where only the rods between the nodes have mass. See that sequence for further details of the allowed walks.
EXAMPLE
a(1)-a(4) = 1 as the only stable walk is a walk straight down from the first node.
a(5) = 3. There is one stable walk with a first step to the right:
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X-----+
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+-----+-----+-----+
,
Assuming a rod mass of q, the total torque to the right of the first node is 2*q*(1/2) + 1*q*1 = 2q. The total torque to the left of the first node is 1*q*(1/2) + 1*q*(3/2) = 2q. This walk can be taken in 2 ways. Thus, with the straight down walk, the total number of stable walks is 2+1 = 3.
CROSSREFS
KEYWORD
nonn,walk,more
AUTHOR
Scott R. Shannon, Sep 13 2020
STATUS
approved