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A371213
Number of ordered factorizations of n into factors > 5.
3
1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3, 2, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 3, 1, 1, 3, 2, 1, 3, 1, 1, 1, 3, 1, 5, 1, 1, 1, 1, 3, 3, 1, 3, 2, 1, 1, 5, 1, 1, 1, 3, 1, 5, 3, 1, 1, 1, 1, 5
OFFSET
1,36
FORMULA
a(1) = 1; a(n) = Sum_{d|n, n/d > 5} a(d).
EXAMPLE
a(42) = 3: 42 = 6*7 = 7*6.
MATHEMATICA
a[n_] := a[n] = If[n == 1, n, Sum[If[n/d > 5, a[d], 0], {d, Divisors[n]}]]; Table[a[n], {n, 1, 96}]
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Mar 15 2024
STATUS
approved