A181766 Numbers k such that 3*k + 7 is not prime.
1, 3, 5, 6, 7, 9, 11, 13, 14, 15, 16, 17, 19, 21, 23, 25, 26, 27, 28, 29, 31, 33, 35, 36, 37, 38, 39, 41, 42, 43, 45, 46, 47, 49, 51, 53, 54, 55, 56, 57, 59, 60, 61, 63, 65, 66, 67, 69, 70, 71, 73, 75, 76, 77, 79, 80, 81, 82, 83, 84, 85, 86, 87, 89, 91, 93, 94, 95, 96, 97, 98
Offset: 1
Examples
Distribution of the even terms in the following triangular array: *; *, 6; *, *,14; *, *,*,*; *,16,*,*,38; *,*,28,*,*,54; *,*, *,*,*, *,*; *,26,*,*,60,*,*,94; *,*,42,*,*,80,*,*,118; *,*,*, *,*,*, *,*, *, *; *,36,*,*,82,*,*,128,*,*,174; *,*,56,*,*,106,*,*,156,*,*,206; etc. where * marks the non-integer values of (4*h*k + 2*k + 2*h - 6)/3 with h >= k >= 1. - _Vincenzo Librandi_, Jan 15 2013
Links
- Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Programs
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Magma
[n: n in [0..100] | not IsPrime(3*n + 7)]; // Vincenzo Librandi, Oct 15 2012
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Mathematica
Select[Range[0, 100], !PrimeQ[3 # + 7] &] (* Vincenzo Librandi, Oct 15 2012 *)
Comments