a(n) = n!*T(n) - 1, where T(n) is the n-th triangular number.

A305739

a(n) = n!*T(n) - 1, where T(n) is the n-th triangular number.

Terms

    a(0) =0a(1) =5a(2) =35a(3) =239a(4) =1799a(5) =15119a(6) =141119a(7) =1451519a(8) =16329599a(9) =199583999a(10) =2634508799a(11) =37362124799a(12) =566658892799

External references