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A120611
Sum of previous term and preceding divisors.
2
1, 2, 3, 4, 7, 8, 15, 19, 20, 27, 31, 32, 47, 48, 66, 72, 90, 111, 115, 116, 123, 127, 128, 175, 183, 187, 188, 242, 245, 253, 254, 384, 610, 613, 614, 617, 618, 624, 690, 826, 836, 862, 865, 866, 869, 870, 891, 922, 925, 926, 929, 930, 982, 985, 986, 989, 990
OFFSET
1,2
LINKS
FORMULA
a(1) = 1, a(2) = 2, for n>=2, a(n+1) = a(n) + sum_{1<=k<n, a(k) divides a(n)} a(k).
MATHEMATICA
a = {1, 2}; Do[AppendTo[a, Plus @@ Intersection[a, Divisors[a[[-1]]]]], {n, 3, 57}]; a (* Ivan Neretin, May 13 2015 *)
CROSSREFS
Sequence in context: A097110 A116961 A300486 * A092063 A227007 A370858
KEYWORD
nonn
AUTHOR
STATUS
approved