This series of values is correct for integer arguments:
sage: gegenbauer(2,1,x) 4*x^2 - 1 sage: gegenbauer(2,1,0) -1 sage: gegenbauer(2,1,1) 3 sage: gegenbauer(2,1,2) 15 But nonzero floats give wrong answers: sage: gegenbauer(2,1,1.) 0.500000000000000 sage: gegenbauer(2,1,2.) 0.875000000000000 And even worse, gegenbauer(2,1,0.) gives the error: OverflowError: numeric::inverse(): division by zero Ralf? -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
