Find a formula for sn Find a formula for s_n, n greaterthanorequalto 1, if s_n is given by 2/5, 3/8, 4/11, 5/14, 6/17,... Solution numerator are in arthematic progression with common difference 1 and first term 2 numerator =1+n denomiator are in arthematic progression with common difference 3 and first term 5 denominator =5+(n-1)3 =2+3n sn=(1+n)/(2+3n).