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A134930 Nearest-neighbors of twin primes. 5
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

LINKS

Table of n, a(n) for n=1..55.

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

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

Sequence in context: A234521 A085125 A194402 * A084562 A240714 A187350

Adjacent sequences:  A134927 A134928 A134929 * A134931 A134932 A134933

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, Nov 16 2007

STATUS

approved

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Last modified September 23 10:30 EDT 2014. Contains 247123 sequences.