A129820 List of pairs of consecutive nonprime odd numbers {m-1,m+1}.

25, 27, 33, 35, 49, 51, 55, 57, 63, 65, 75, 77, 85, 87, 91, 93, 93, 95, 115, 117, 117, 119, 119, 121, 121, 123, 123, 125, 133, 135, 141, 143, 143, 145, 145, 147, 153, 155, 159, 161, 169, 171, 175, 177, 183, 185, 185, 187, 187, 189

Offset

1,1

Links

Table of n, a(n) for n=1..50.

Mathematica

Flatten[Table[If[OddQ[n - 1] && PrimeQ[n - 1] == False && PrimeQ[n + 1] == False, {{n - 1}, {n + 1}}, {}], {n, 2, 200}]]
Select[Partition[Range[1, 201, 2], 2, 1], NoneTrue[#, PrimeQ]&]//Flatten (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 09 2019 *)

Crossrefs

Cf. A061673, A093708.

Sequence in context: A287763 A239523 A361821 * A096522 A195351 A015734

Adjacent sequences: A129817 A129818 A129819 * A129821 A129822 A129823

Keyword

nonn

Author

Roger L. Bagula, May 20 2007

Status

approved