[sage-support] Multiply first terms of Dirichlet powerseries

[Ton Biegstraaten]

Hi, As an example I multiplied the first terms of 2 Dirichlet powerseries. The result is also a Dirichlet powerserie, but how do I get the result in that shape? --- sage: a(x) = sum([1/(n^x) for n in range(1,4)]) sage: b(x) = a(x)*a(x) sage: print "a(x): ",a(x), "\nproduct: ", a(x)*a(x), "\nb(x): ", b(x).expand() a(x): 1/2^x + 1/3^x + 1 product: (1/2^x + 1/3^x + 1)^2 b(x): 2/2^x + 1/(2^x)^2 + 2/3^x + 2/(2^x*3^x) + 1/(3^x)^2 + 1 --- I like to get things like 2^x*3^x => 6^x and combine all n^x terms, as I'm only interested in the denominators of that terms. The result should be: 1 + 2/2^x + 2/3^x + 3/4^x ... each denominator is the number of divisors of the number in the nominator if you use enough terms in the original series. Is that possible and of course how? Thanks, Ton --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---