login
A078847
Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <= 6 (i.e., when d = 2, 4 or 6) and forming pattern = [2, 4, 6]; short notation = [246] d-pattern.
28
17, 41, 227, 347, 641, 1091, 1277, 1427, 1487, 1607, 2687, 3527, 3917, 4001, 4127, 4637, 4787, 4931, 8231, 9461, 10331, 11777, 12107, 13901, 14627, 20747, 21557, 23741, 25577, 26681, 26711, 27737, 27941, 28277, 29021, 31247, 32057, 32297
OFFSET
1,1
COMMENTS
Subsequence of A022004. - R. J. Mathar, Feb 10 2013
a(n) + 12 is the greatest term in the sequence of 4 consecutive primes with 3 consecutive gaps 2, 4, 6. - Muniru A Asiru, Aug 03 2017
FORMULA
Primes p=prime(i) such that prime(i+1) = p+2, prime(i+2) = p+2+4, prime(i+3) = p+2+4+6.
EXAMPLE
17, 17+2 = 19, 17+2+4 = 23, 17+2+4+6 = 29 are consecutive primes.
MATHEMATICA
d = Differences[Prime[Range[10000]]]; Prime[Flatten[Position[Partition[d, 3, 1], {2, 4, 6}]]] (* T. D. Noe, May 23 2011 *)
Transpose[Select[Partition[Prime[Range[10000]], 4, 1], Differences[#] == {2, 4, 6}&]][[1]] (* Harvey P. Dale, Aug 07 2013 *)
CROSSREFS
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].
Cf. A190814[2,4,6,8], A190817[2,4,6,8,10], A190819[2,4,6,8,10,12], A190838[2,4,6,8,10,12,14]
Sequence in context: A165668 A269425 A164602 * A201028 A328022 A287308
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 11 2002
EXTENSIONS
Listed terms verified by Ray Chandler, Apr 20 2009
Additional cross references from Harvey P. Dale, May 10 2014
STATUS
approved