[seqfan] A102421; Start with 2n+1, multiply by 3 and add 1 and divide out any power of 2; ....

[David Corneth]

Hi,

Can I get an extra pair of eyes over at A102421? It seems data was
inconsistent with a comment even before I got there.
It describes a function that, well, takes a number and then returns another
number.
Like after some magic, 17 becomes 19... according to a comment. But data
says 17 becomes 19.
Then 19 becomes 43.

Upon inspection,
a(8) = a((17 - 1)/2) = 19.
a(9) = a((19 - 1)/2) = 43

Could that be it?
There's no reference to (n-1)/2 so that'd be guessing. Or should that be
read from take 2n+1 in name?
One could say if x = 2n + 1 then n = (x-1)/2 but to me that doesn't follow
from the name.

Best,
David