A371213 Number of ordered factorizations of n into factors > 5.

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

Links

Table of n, a(n) for n=1..96.

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}]

Crossrefs

Cf. A002033, A017900, A074206, A185326, A371209, A371211, A371212.

Sequence in context: A360119 A033630 A308608 * A323719 A220122 A101446

Adjacent sequences: A371210 A371211 A371212 * A371214 A371215 A371216

Keyword

nonn

Author

Ilya Gutkovskiy, Mar 15 2024

Status

approved