A064409 Positive even numbers not of the form A001359(i) + A006512(j) for integers i and j.

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

Offset

1,1

Comments

This is different from A007534, which gives positive even numbers which are not the same of a pair of twin primes. The old definition of the present sequence was misleading. - N. J. A. Sloane, Feb 16 2024

Links

A.H.M. Smeets, Table of n, a(n) for n = 1..20177

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 current 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

Cf. A001359, A006512, A007534.

Sequence in context: A358671 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