term-by-term sum =  1.5961632439130233 using 20 terms

term-by-term sum =  1.5759958390005426 using 13 terms

exact value      =  1.6449340668482264

accelerated sum  =  1.6449340669228176 using 13 terms

estimated error  =  0.0000000000888360

actual error     =  0.0000000000745912