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A146297 Integers which are not the sum of a 6-almost prime and a prime. 4

%I #7 Jun 16 2019 22:30:28

%S 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,

%T 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,

%U 50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,68,70,72,73,74,76,78,79

%N Integers which are not the sum of a 6-almost prime and a prime.

%C Largest known term is 446185740 (see b-file). No more terms < 10^9.

%H Donovan Johnson, <a href="/A146297/b146297.txt">Table of n, a(n) for n=2..20150</a>

%e 68 is in this sequence because no 6-almost prime and a prime sum to 68. 69 is not in this sequence because the sum of 64 (6-almost prime) and 5 (prime) is 69.

%t Complement[Range[1000], Union@Flatten@Outer[Plus, Select[Range[1000], PrimeOmega[#] == 6 &], Prime[Range[PrimePi[1000]]]]] (* _Robert Price_, Jun 16 2019 *)

%Y Cf. A000040, A046306, A130588, A146295, A146296.

%K nonn

%O 2,1

%A _Donovan Johnson_, Nov 05 2008

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Last modified April 23 07:42 EDT 2024. Contains 371905 sequences. (Running on oeis4.)