How to retrieved protein Fasta sequence from accession number by Entrez

AF131201
AF326487
AF326488
AF326489
AF326490

This are the some the accession number of protein. Firstly i dont know what kind of accession number is this. beacuse usually protein accession number start with XP_/NP_.
Problem arise when i try the following command using the accession number given above:

1. esearch -db protein -query “AF131201” | efetch -format fasta > output.fasta
2. esearch -db nuccore -query “AF131201” | elink -target protein | efetch -db protein -format fasta
3. Or directly submitting a bunch of accession number file to Entrez batch.

But i got nothing.
Reason for the error is very sure due to the accession number i used.
Can somebody help a way to solve this.

Thanks