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A350748
Smallest number not already in the sequence that is a divisor of A002182(n).
0
1, 2, 4, 3, 6, 8, 9, 12, 5, 10, 15, 16, 18, 20, 7, 14, 21, 24, 28, 27, 30, 35, 32, 25, 11, 36, 40, 22, 33, 42, 44, 45, 48, 54, 55, 50, 56, 13, 26, 39, 52, 60, 63, 65, 66, 70, 64, 72, 75, 77, 78, 80, 17, 84, 34, 51, 68, 85, 88, 90, 91, 96, 99, 81, 19, 100, 102
OFFSET
1,2
EXAMPLE
a(3) cannot be 3 because 3 is not a divisor of A002182(3)=4. a(4), however, can be 3 because 3 is a divisor of A002182(4)=6.
MATHEMATICA
a[n_]:=a[n]=Min@Select[Divisors[max=t=k=0; While[t<n, k++; While[(d=DivisorSigma[0, k])<=max, k++]; max=d; t++]; k], FreeQ[Array[a, n-1], #]&]; Array[a, 30] (* Giorgos Kalogeropoulos, Jan 13 2022 *)
CROSSREFS
Cf. A002182.
Sequence in context: A349370 A137621 A242705 * A357910 A367082 A039864
KEYWORD
nonn
AUTHOR
J. Lowell, Jan 13 2022
EXTENSIONS
More terms from Amiram Eldar, Jan 13 2022
STATUS
approved