A325274 Sum of the omega-sequence of n!.

0, 0, 1, 5, 9, 13, 14, 20, 23, 25, 24, 30, 33, 35, 35, 40, 44, 46, 49, 51, 54, 56, 59, 61, 65, 67, 72, 75, 78, 80, 83, 85, 90, 90, 95, 97, 101, 103, 105, 106, 110, 112, 115, 117, 122, 125, 127, 129, 134, 136, 139, 140, 143, 145, 149, 153, 157, 159, 160, 162

Offset

0,4

Comments

We define the omega-sequence of n (row n of A323023) to have length A323014(n) = adjusted frequency depth of n, and the k-th term is Omega(red^{k-1}(n)), where Omega = A001222 and red^{k} is the k-th functional iteration of red = A181819, defined by red(n = p^i*...*q^j) = prime(i)*...*prime(j) = product of primes indexed by the prime exponents of n. For example, we have 180 -> 18 -> 6 -> 4 -> 3, so the omega-sequence of 180 is (5,3,2,2,1), with sum 13.

Links

Table of n, a(n) for n=0..59.

Mathematica

omseq[n_Integer]:=If[n<=1, {}, Total/@NestWhileList[Sort[Length/@Split[#]]&, Sort[Last/@FactorInteger[n]], Total[#]>1&]];
Table[Total[omseq[n!]], {n, 0, 100}]

Crossrefs

a(n) = A056239(A325275(n)).

Cf. A000142, A006939, A303555, A323023, A325238, A325272, A325273, A325276, A325277.

Omega-sequence statistics: A001222 (first omega), A001221 (second omega), A071625 (third omega), A323022 (fourth omega), A304465 (second-to-last omega), A182850 or A323014 (length/frequency depth), A325248 (Heinz number), A325249 (sum).

Sequence in context: A130333 A304868 A080579 * A303264 A165971 A160522

Adjacent sequences: A325271 A325272 A325273 * A325275 A325276 A325277

Keyword

nonn

Author

Gus Wiseman, Apr 18 2019

Status

approved