Sum[1/(a + (1/2) (-1 + n) n), {n, 1, Infinity}]==(2 π tan(1/2 π sqrt(1 - 8 a)))/sqrt(1 - 8 a)Sum[1/(a + (1/2) (-1 + n) n), {n, 1, Infinity}]==(2 π tan(1/2 π sqrt(1 - 8 a)))/sqrt(1 - 8 a)

• Natural Language
• Math Input