login
A121644
Slowest increasing sequence with squarefree cumulative sums.
3
1, 2, 3, 4, 5, 6, 8, 9, 13, 14, 17, 19, 21, 23, 25, 27, 29, 31, 33, 36, 39, 41, 43, 44, 45, 48, 49, 50, 52, 53, 59, 61, 63, 64, 65, 67, 68, 69, 72, 73, 75, 77, 82, 84, 86, 87, 88, 89, 91, 92, 93, 94, 96, 98, 99, 100, 101, 102, 104, 106, 108, 110, 116, 117, 119, 120, 121, 123
OFFSET
1,2
MATHEMATICA
a = {1}; Do[k = 1; While[Nand[k > a[[n]], SquareFreeQ[Sum[a[[i]], {i, n}] + k]], k++]; AppendTo[a, k], {n, 67}]; a (* Michael De Vlieger, Sep 03 2015 *)
CROSSREFS
Cf. A084693 (non-monotonic version).
Sequence in context: A190232 A084693 A276765 * A259623 A305734 A002242
KEYWORD
nonn
AUTHOR
Zak Seidov, Aug 13 2006
STATUS
approved