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A114405 5-almost prime gaps. First differences of A014614. 4

%I #11 Sep 28 2019 15:38:19

%S 16,24,8,28,4,8,42,6,8,4,20,8,35,9,12,6,2,8,20,4,8,56,10,14,4,9,3,12,

%T 20,10,6,8,4,28,4,20,32,15,21,4,2,18,4,14,26,4,15,5,4,4,8,4,2,26,16,6,

%U 2,8,20,48,20,34,6,3,27,2,4,20,1,7,16,8,4,4,6,30,6,6,12,6,3,11

%N 5-almost prime gaps. First differences of A014614.

%C First occurrences of a(n)=1,2,3,.. are at n=69, 17, 27, 5, 48, 8, 70, 3, 14, 23, 82, 15, 150, 24, 38, 1, 172, 42, 258, 11, 39, 135, 102, 2, 779, 45, 65, 4, 518, 76, 263, 37, 211, 62, 13, 1009, 2463, 606, 254, 151, 3348, 7, 4513,... - _R. J. Mathar_, Oct 06 2007

%H R. J. Mathar, <a href="/A114405/b114405.txt">Table of n, a(n) for n = 1..9999</a>

%F a(n) = A014614(n+1) - A014614(n).

%e a(1) = 16 = 48-32 where 32 is the first 5-almost prime and 48 is the second.

%e a(2) = 24 = 72-48.

%e a(3) = 8 = 80-72.

%e a(4) = 28 = 108-80.

%e a(5) = 4 = 112-108.

%e a(6) = 8 = 120-112.

%e a(7) = 42 = 162-120.

%e a(8) = 6 = 168-162.

%e a(13) = 35 = 243-208.

%e a(22) = 56 = 368-312.

%t Differences[Select[Range[2000],PrimeOmega[#]==5&]] (* _Harvey P. Dale_, Sep 28 2019 *)

%Y Cf. A014614, A065516, A111870, A111871, A114403-A114411, A114412-A114422.

%K easy,nonn

%O 1,1

%A _Jonathan Vos Post_, Nov 25 2005

%E More terms from _R. J. Mathar_, Oct 06 2007

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Last modified April 16 13:59 EDT 2024. Contains 371734 sequences. (Running on oeis4.)