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A045767 Number of prime factors of triple factorials n!!! (A007661), with multiplicity. 1

%I #12 Jul 22 2022 17:47:44

%S 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,

%T 16,25,19,21,27,21,23,31,22,25,33,26,26,36,27,29,39,29,30,44,31,33,46,

%U 34,34,50,36,38,52,38,39,56,39,41,59,45,43,62,46,46,64,49,47,69,50,49

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

%H Harvey P. Dale, <a href="/A045767/b045767.txt">Table of n, a(n) for n = 1..1000</a>

%t 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 *)

%t Table[PrimeOmega[Times@@Range[n,1,-3]],{n,80}] (* _Harvey P. Dale_, Apr 11 2020 *)

%K nonn,easy

%O 1,4

%A _Jeff Burch_

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Last modified April 18 18:58 EDT 2024. Contains 371781 sequences. (Running on oeis4.)