Group the natural numbers such that the n-th group contains n terms and the group sum is the smallest possible prime: (2), (1, 4), (3, 5, 9), (6, 7, 8, 10), (11, 12, 13, 14, 17), (15, 16, 18, 19, 20, 21), ... Sequence gives group sums.
A075345
Group the natural numbers such that the n-th group contains n terms and the group sum is the smallest possible prime: (2), (1, 4), (3, 5, 9), (6, 7, 8, 10), (11, 12, 13, 14, 17), (15, 16, 18, 19, 20, 21), ... Sequence gives group sums.
Terms
- a(0) =2a(1) =5a(2) =17a(3) =31a(4) =67a(5) =109a(6) =179a(7) =257a(8) =373a(9) =503a(10) =673a(11) =877a(12) =1093a(13) =1381a(14) =1693a(15) =2063a(16) =2459a(17) =2927a(18) =3449a(19) =4001a(20) =4637a(21) =5347a(22) =6089a(23) =6947a(24) =7817a(25) =8783a(26) =9857a(27) =10987a(28) =12211a(29) =13513
External references
- oeis: A075345