A276829 a(n) = the least positive number m not yet used such that prime(n) + m and prime(n+1) + m are prime.

2, 6, 12, 18, 24, 42, 48, 8, 30, 10, 60, 66, 36, 14, 20, 78, 22, 96, 108, 28, 84, 68, 102, 126, 90, 120, 72, 54, 114, 150, 26, 132, 144, 162, 16, 34, 186, 56, 50, 168, 156, 228, 204, 222, 40, 46, 174, 192, 210, 38, 180, 138, 80, 74, 44, 252, 76, 336, 240, 216, 264, 306, 258, 300, 246, 52

Offset

2,1

Comments

Apparently the only absent positive even integer is 4.

Links

Zak Seidov, Table of n, a(n) for n = 2..1001

Mathematica

s={}; p=3; q=5; Do[m=2; While[MemberQ[s, m]||!PrimeQ[m+p]||!PrimeQ[m+q], m=m+2]; AppendTo[s, m]; p=q; q=NextPrime[q], {100}]; s

Crossrefs

Cf. A247097.

Sequence in context: A085345 A348774 A265843 * A032371 A162802 A330320

Adjacent sequences: A276826 A276827 A276828 * A276830 A276831 A276832

Keyword

nonn

Author

Zak Seidov, Nov 10 2016

Status

approved