1,2

a(n) = a(n-1) + q^{(n-1)} = {(q^n - 1) / (q - 1)}

Sequence in context: A103581 A087545 A078252 this_sequence A015592 A122574 A084031

Adjacent sequences: A014990 A014991 A014992 this_sequence A014994 A014995 A014996

sign,easy

Olivier Gerard (olivier.gerard(AT)gmail.com)