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A153235 Numbers n such that 8*n+7 is not prime. 1
1, 4, 6, 7, 10, 11, 13, 14, 16, 17, 19, 21, 22, 25, 26, 28, 30, 31, 34, 35, 36, 37, 39, 40, 41, 42, 43, 46, 48, 49, 50, 51, 52, 55, 56, 58, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 76, 77, 79, 81, 82, 83, 84, 85, 86, 87, 88, 91, 94, 95, 96, 97, 98, 99, 100, 101 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

Distribution of the terms in the following triangular array:

*;

1,*;

*,*,*;

*,*,7,*;

*,6,*,*,*;

4,*,*,*,17,*;

*,*,*,16,*,*,*;

*,*,14,*,*,*,31,*;

*,11,*,*,*,30,*,*,*;

7,*,*,*,28,*,*,*,49,*:

*,*,*,25,*,*,*,48,*,*,*;

*,*,21,*,*,*,46,*,*,*,71,*; etc.

where * marks the non-integer values of (2*h*k + k + h - 3)/4 with h >= k >= 1. - Vincenzo Librandi, Jan 15 2013

MATHEMATICA

Select[Range[0, 200], !PrimeQ[8 # + 7] &] (* Vincenzo Librandi, Jan 12 2013 *)

PROG

(MAGMA) [n: n in [0..110] | not IsPrime(8*n+7)]; // Vincenzo Librandi, Jan 12 2013

CROSSREFS

Cf. A139487.

Sequence in context: A123088 A256657 A189085 * A286491 A133483 A153082

Adjacent sequences:  A153232 A153233 A153234 * A153236 A153237 A153238

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Dec 21 2008

STATUS

approved

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Last modified September 21 14:54 EDT 2020. Contains 337272 sequences. (Running on oeis4.)