a(n) = LCM_{k=1..n} (2^k - 1).

A034268

a(n) = LCM_{k=1..n} (2^k - 1).

Terms

    a(0) =1a(1) =3a(2) =21a(3) =105a(4) =3255a(5) =9765a(6) =1240155a(7) =21082635a(8) =1539032355a(9) =16929355905

External references