OFFSET
1,1
LINKS
R. J. Mathar, Table of n, a(n) for n = 1..1000
FORMULA
Primes p = p_(i) such that p_(i+1) = p + 6, p_(i+2) = p + 6 + 4, p_(i+3) = p + 6 + 4 + 6.
EXAMPLE
p=73, 73 + 6 = 79, 73 + 6 + 4 = 83, 73 + 6 + 4 + 6 = 89 are consecutive primes.
MAPLE
N:=10^4: # to get all terms <= N.
Primes:=select(isprime, [seq(i, i=3..N+16, 2)]):
Primes[select(t->[Primes[t+1]-Primes[t], Primes[t+2]-Primes[t+1],
Primes[t+3]-Primes[t+2]]=[6, 4, 6], [$1..nops(Primes)-3])]; # Muniru A Asiru, Aug 04 2017
MATHEMATICA
Transpose[Select[Partition[Prime[Range[10000]], 4, 1], Differences[#]=={6, 4, 6}&]][[1]] (* Harvey P. Dale, Apr 22 2014 *)
CROSSREFS
Subsequence of A078562.
Cf. analogous prime quadruple sequences with various possible {2, 4, 6}-difference-patterns in brackets: A007530[242], A078847[246], A078848[264], A078849[266], A052378[424], A078850[426], A078851[462], A078852[466], A078853[624], A078854[626], A078855[642], A078856[646], A078857[662], A078858[664], A033451[666].
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 11 2002
EXTENSIONS
Listed terms verified by Ray Chandler, Apr 20 2009
Name simplified by Michel Marcus, Aug 11 2017
STATUS
approved