This looks like a bug, you get the sum unevaluated. You can as a workaround evaluate it manually. I get:
print(h3(3,h3n=5).unhold()) 20 Thanks for the report. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
