A129822 - OEIS

A129822

Array read by rows: each row lists three consecutive nonprime odd numbers.

91, 93, 95, 115, 117, 119, 117, 119, 121, 119, 121, 123, 121, 123, 125, 141, 143, 145, 143, 145, 147, 183, 185, 187, 185, 187, 189, 201, 203, 205, 203, 205, 207, 205, 207, 209, 213, 215, 217, 215, 217, 219, 217, 219, 221, 243, 245, 247, 245, 247, 249, 285

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10002

MAPLE

a:=proc(n) if isprime(2*n-1)=false and isprime(2*n+1)=false and isprime(2*n+3)=false then 2*n-1, 2*n+1, 2*n+3 else fi end: seq(a(n), n=1..150);

MATHEMATICA

Flatten[Table[If[OddQ[n - 1] && PrimeQ[n - 1] == False && PrimeQ[n + 1] == False && PrimeQ[n + 3] == False, {{n - 1}, {n + 1}, {n + 3}}, {}], {n, 2, 300}]]

Select[Partition[Range[1, 301, 2], 3, 1], NoneTrue[#, PrimeQ]&]//Flatten (* Harvey P. Dale, Jul 16 2021 *)

CROSSREFS

Cf. A099019 (second column), A161945 (first column).

Sequence in context: A043811 A043820 A077685 * A321998 A351624 A020318

Adjacent sequences: A129819 A129820 A129821 * A129823 A129824 A129825

KEYWORD

nonn,tabf

AUTHOR

Roger L. Bagula, May 20 2007

EXTENSIONS

Edited by N. J. A. Sloane, Jun 09 2007

Definition modified by Harvey P. Dale, Jul 16 2021

STATUS

approved