Group the natural numbers >= 1 so that the n-th group contains n(n+1)/2 numbers and obtain the group sum.
A095166
Group the natural numbers >= 1 so that the n-th group contains n(n+1)/2 numbers and obtain the group sum.
Terms
- a(0) =1a(1) =9a(2) =45a(3) =155a(4) =420a(5) =966a(6) =1974a(7) =3690a(8) =6435a(9) =10615a(10) =16731a(11) =25389a(12) =37310a(13) =53340a(14) =74460a(15) =101796a(16) =136629a(17) =180405a(18) =234745a(19) =301455a(20) =382536a(21) =480194a(22) =596850a(23) =735150a(24) =897975a(25) =1088451a(26) =1309959a(27) =1566145a(28) =1860930a(29) =2198520
External references
- oeis: A095166