OFFSET
1,1
COMMENTS
This sequence consists of the number 2 followed by the triple composites: A134928.
LINKS
FORMULA
a(1)=2. For n>2, a(n)=A134928(n-1)
EXAMPLE
2, 4 and 6 are nearest-neighbors of twin primes because 3 and 5 are twin primes.
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 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Nov 16 2007
STATUS
approved