A045767 Number of prime factors of triple factorials n!!! (A007661), with multiplicity.

0, 1, 1, 2, 2, 3, 3, 5, 5, 5, 6, 8, 6, 8, 10, 10, 9, 13, 11, 12, 15, 13, 13, 19, 15, 15, 22, 18, 16, 25, 19, 21, 27, 21, 23, 31, 22, 25, 33, 26, 26, 36, 27, 29, 39, 29, 30, 44, 31, 33, 46, 34, 34, 50, 36, 38, 52, 38, 39, 56, 39, 41, 59, 45, 43, 62, 46, 46, 64, 49, 47, 69, 50, 49

Offset: 1

Author

Jeff Burch

Keywords

• nonn
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Mathematica

Rest[PrimeOmega/@RecurrenceTable[{a[0]==a[1]==1,a[2]==2,a[n]==n*a[n-3]},a,{n,80}]] (* Harvey P. Dale, May 17 2012 *)
Table[PrimeOmega[Times@@Range[n,1,-3]],{n,80}] (* Harvey P. Dale, Apr 11 2020 *)