a(n) = sum of sums of all sets of three distinct preceding terms otherwise a(n) = n for n <= 3.

A129379

a(n) = sum of sums of all sets of three distinct preceding terms otherwise a(n) = n for n <= 3.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =6a(4) =36a(5) =288a(6) =3360a(7) =55440a(8) =1241856a(9) =36427776a(10) =1358235648a(11) =62818398720

External references