A134930 Nearest-neighbors of twin primes.

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 28, 30, 32, 40, 42, 44, 58, 60, 62, 70, 72, 74, 100, 102, 104, 106, 108, 110, 136, 138, 140, 148, 150, 152, 178, 180, 182, 190, 192, 194, 196, 198, 200, 226, 228, 230, 238, 240, 242, 268, 270, 272, 280, 282, 284

Offset: 1

Author

Omar E. Pol, Nov 16 2007

Keywords

• easy
• nonn

Comments

This sequence consists of the number 2 followed by the triple composites: A134928.

Examples

			2, 4 and 6 are nearest-neighbors of twin primes because 3 and 5 are twin primes.
		

Links

• Omar E. Pol, Determinacion geometrica de los numeros primos y compuesto.

Programs

Mathematica

f[{a_,b_}]:={a-1,a+1,b+1}; Union[Flatten[f/@Select[Partition[Prime[ Range[ 100]],2,1], Last[#]-First[#]==2&]]] (* Harvey P. Dale, Aug 16 2011 *)

Formula

a(1)=2. For n>2, a(n)=A134928(n-1)