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A064409 Even numbers not the sum of a pair twin primes, one the lesser and the other the greater. 0
2, 4, 6, 14, 20, 26, 28, 32, 38, 40, 44, 50, 52, 56, 58, 62, 68, 70, 74, 80, 82, 86, 88, 92, 94, 96, 98, 100, 104, 110, 116, 118, 122, 124, 128, 130, 134, 136, 140, 146, 148, 152, 158, 160, 164, 166, 170, 172, 176, 178, 182, 188, 190, 194, 200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

The lesser of the twin primes < 200 are 3, 5, 11, 17, 29, 41, 59, 71, 101, 107, 137, 149, 179, 191, 197 and the greater of the twin primes < 200 are 5, 7, 13, 19, 31, 43, 61, 73, 103, 109, 139, 151, 181, 193, 199. 20 is in the above sequence because no combination of any two numbers from each set just enumerated can be summed to make 20.

MATHEMATICA

p = Select[ Range[ 200 ], PrimeQ[ # ] && PrimeQ[ # + 2 ] & ]; q = p + 2; Complement[ Table[ n, {n, 2, 200, 2} ], Union[ Flatten[ Table[ p[ [ i ] ] + q[ [ j ] ], {i, 1, 15}, {j, 1, 15} ] ] ] ]

CROSSREFS

Sequence in context: A124693 A095698 A277909 * A225078 A032353 A062112

Adjacent sequences:  A064406 A064407 A064408 * A064410 A064411 A064412

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 29 2001

STATUS

approved

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Last modified January 27 12:01 EST 2020. Contains 331295 sequences. (Running on oeis4.)