[seqfan] Riffle shuffle sequence A051732 needs program and b-file

[Neil Sloane]

Dear Seq Fans, A correspondent, Anthony C Robin, wrote to me about
a sequence arising from riffle shuffles (see A051733, A217948). They both
need
more terms. But the basic sequence is A051732, which needs
a computer program and a b-file, in case someone can help.
This should be a 2-line program in Magma (or maybe in Mma,
which does have a Riffle command).

Also, what is the connection between A002326 and A051732? Often one is
twice the other!

Neil