A166685 Odd numbers that are the sum of two consecutive nonprimes.

1, 5, 17, 19, 29, 31, 41, 43, 49, 51, 53, 55, 65, 67, 69, 71, 77, 79, 89, 91, 97, 99, 101, 103, 109, 111, 113, 115, 125, 127, 129, 131, 137, 139, 149, 151, 153, 155, 161, 163, 169, 171, 173, 175, 181, 183, 185, 187, 189, 191, 197, 199, 209, 211, 221, 223, 229

Offset: 1

Author

Juri-Stepan Gerasimov, Oct 18 2009

Keywords

• nonn

Examples

			a(1)=0(1st nonprime)+1(2nd nonprime)=1(odd);
a(2)=1(2nd nonprime)+4(3rd nonprime)=5(odd).
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A118134, A141468, A163467.

Programs

Mathematica

Select[Total/@Partition[Select[Range[0,200],!PrimeQ[#]&],2,1],OddQ] (* Harvey P. Dale, Mar 07 2020 *)

Extensions

Entries checked by R. J. Mathar, Apr 24 2010