OFFSET
3,1
LINKS
Michael De Vlieger, Table of n, a(n) for n = 3..10000
FORMULA
EXAMPLE
Table relating sequences b = A109890, s = A109735, c = A371909. a(n) = c(n) implies both A111315(i) = n and A111316(i) = b(n) = s(n-1).
n b(n) s(n-1) a(n) c(n) i
--------------------------------------
3 3 = 3 2 2 1
4 6 = 6 4 4 2
5 4 12 4 6
6 8 16 4 5
7 12 24 7 8
8 9 36 6 9
9 5 45 3 6
10 10 50 4 6
11 15 60 9 12
12 25 75 5 6
...
222 113573 = 113573 4 4 3
...
232 230801 = 230801 4 4 4
...
279 941071 = 941071 4 4 5
...
MATHEMATICA
nn = 120; c[_] := False;
Array[Set[{a[#], c[#]}, {#, True}] &, 2]; s = a[1] + a[2];
Reap[Do[d = Divisors[s]; k = SelectFirst[d, ! c[#] &];
c[k] = True; Sow[FirstPosition[d, k][[1]]];
s += k, {n, 3, nn}] ][[-1, 1]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Apr 26 2024
STATUS
approved