The On-Line Encyclopedia of Integer Sequences (OEIS)

A242515 revision #7

A242515

Numbers n such that 12n+1, 12n+5, 12n+7, 12n+11 are all composite numbers.

44, 70, 72, 74, 105, 111, 112, 132, 137, 140, 147, 154, 163, 170, 182, 193, 202, 207, 209, 235, 245, 248, 252, 258, 262, 273, 285, 312, 315, 317, 322, 329, 331, 336, 345, 347, 349, 359, 369, 372, 377, 384, 392, 397, 403, 404, 422, 427, 437

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..49.

EXAMPLE

a(1) = 44; 44*12+1=529, 44*12+5=533, 44*12+7=535, 44*12+11=539, and 529, 533, 535 and 539 are all composites.

PROG

(Pari)

for(i=0, 1000, if(!isprime(12*i+1) && !isprime(12*i+5) && !isprime(12*i+7) && !isprime(12*i+11), print1(i", "))) \\ Lear Young, May 16 2014

CROSSREFS

Subsequence of A153383.

Sequence in context: A111494 A092025 A250329 * A156812 A171665 A348098

Adjacent sequences: A242512 A242513 A242514 * A242516 A242517 A242518

KEYWORD

nonn

AUTHOR

Lear Young, May 16 2014

STATUS

proposed