A190814 Initial primes of 5 consecutive primes with consecutive gaps 2, 4, 6, 8.

347, 1427, 2687, 4931, 13901, 21557, 23741, 27941, 28277, 31247, 32057, 33617, 45821, 55661, 55817, 68207, 68897, 91571, 128657, 128981, 167621, 179897, 193871, 205421, 221717, 234191, 239231, 258107, 258611, 259157, 278807, 302831, 305477, 348431, 354371

Offset

1,1

Comments

All terms = {11,17} mod 30.

a(n) + 20 is the greatest term in the sequence of 5 consecutive primes with 4 consecutive gaps 2, 4, 6, 8. - Muniru A Asiru, Aug 03 2017

Links

Zak Seidov, Table of n, a(n) for n = 1..2000

Example

Prime(69..73) = {347, 349, 353, 359, 367} and 349 - 347 = 2, 353 - 349 = 4, 359 - 353 = 6, 367 - 359 = 8.

Maple

N:= 10^6: # to get all terms <= N
Primes:= select(isprime, [seq(i, i=3..N+20, 2)]):
Primes[select(t -> [Primes[t+1]-Primes[t], Primes[t+2]-Primes[t+1], Primes[t+3]-Primes[t+2], Primes[t+4]-Primes[t+3]] = [2, 4, 6, 8], [$1..nops(Primes)-4])]; # Robert Israel, Aug 03 2017

Mathematica

d = Differences[Prime[Range[100000]]]; Prime[Flatten[Position[Partition[d, 4, 1], {2, 4, 6, 8}]]] (* T. D. Noe, May 23 2011 *)
Select[Partition[Prime[Range[31000]], 5, 1], Differences[#]=={2, 4, 6, 8}&][[All, 1]] (* Harvey P. Dale, Jul 03 2020 *)

Crossrefs

Subsequence of A190799, also subsequence of A078847.

Cf. A190792, A190817, A190819, A190838.

Sequence in context: A054823 A343701 A142369 * A012868 A343303 A226669

Adjacent sequences: A190811 A190812 A190813 * A190815 A190816 A190817

Keyword

nonn

Author

Zak Seidov, May 20 2011

Extensions

Additional cross references from Harvey P. Dale, May 10 2014

Status

approved