Group the natural numbers such that the n-th group sum is divisible by the n-th triangular number: (1), (2, 3, 4), (5, 6, 7), (8, 9, 10, 11, 12), (13, 14, 15, 16, 17), (18, 19, 20, 21, 22, 23, 24), ... Sequence contains the group sum.
A086500
Group the natural numbers such that the n-th group sum is divisible by the n-th triangular number: (1), (2, 3, 4), (5, 6, 7), (8, 9, 10, 11, 12), (13, 14, 15, 16, 17), (18, 19, 20, 21, 22, 23, 24), ... Sequence contains the group sum.
Terms
- a(0) =1a(1) =9a(2) =18a(3) =50a(4) =75a(5) =147a(6) =196a(7) =324a(8) =405a(9) =605a(10) =726a(11) =1014a(12) =1183a(13) =1575a(14) =1800a(15) =2312a(16) =2601a(17) =3249a(18) =3610a(19) =4410a(20) =4851a(21) =5819a(22) =6348a(23) =7500a(24) =8125a(25) =9477a(26) =10206a(27) =11774a(28) =12615a(29) =14415
External references
- oeis: A086500