Tootfinder

I just wanted to quickly typst an example for the lecture tomorrow and suddenly I'm on #oeis again: https://oeis.org/A088138
I think this sequence is the result of the tri-diagonal determinant of twos, but it does not appear in the OEIS comments at all!
In fact, most comments are about a sequence with different signs, for example the first comment gives the generating function for that other sequence. Why?
The recursion is a_n = 2 a_(n-1) - 4 a_(n-2) and the formula is in the 2. pic, I hope.

Meine Lieblingswebseite ist OEIS.org und das sage ich auch in der Öffentlichkeit. Jetzt meine Frage: Wie viele Daumen nach oben gebt ihr für OEIS?
https://youtube.com/shorts/pVoT9Ykv63s?feature=share
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