A190838 Initial primes of 8 consecutive primes with 7 consecutive gaps 2, 4, 6, 8, 10, 12, 14.

128981, 21456047, 34864211, 51867197, 55793951, 69726647, 113575727, 180078317, 207664397, 232728647, 342241967, 382427027, 382533311, 470463011, 558791327, 591360851, 603413801, 749930717, 838115711, 926976431, 965761397, 1007421251, 1109867567, 1278189947

Offset

1,1

Comments

a(1) = 128981 = A190819(1), a(2) = 21456047 = A190819(14).

a(n) + 56 is the greatest term in the sequence of 8 consecutive primes with 7 consecutive gaps 2, 4, 6, 8, 10, 12, 14. - Muniru A Asiru, Aug 10 2017

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Maple

N:=10^8:  # to get all terms <= N.
Primes:=select(isprime, [seq(i, i=3..N+56, 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], Primes[t+5]-
  Primes[t+4], Primes[t+6]-Primes[t+5] , Primes[t+7]-Primes[t+6] ]=
[2, 4, 6, 8, 10, 12, 14], [$1..nops(Primes)-7])]; # Muniru A Asiru, Aug 04 2017

Mathematica

Transpose[Select[Partition[Prime[Range[65000000]], 8, 1], Differences[#] =={2, 4, 6, 8, 10, 12, 14}&]][[1]] (* Harvey P. Dale, May 10 2014 *)

Prog

(PARI) list(lim)=my(v=List(), p=128981, t); forprime(q=p+2, lim+56, if(q-p-t==2, t+=2; if(t==14, listput(v, q-56); t=0), t=0); p=q); Vec(v) \\ Charles R Greathouse IV, Aug 10 2017

Crossrefs

Subsequence of A190819.

Subsequence of A187060. - Michel Marcus, Aug 10 2017

Cf. A078847, A190814, A190817.

Sequence in context: A151812 A224585 A190819 * A237072 A232122 A232420

Adjacent sequences: A190835 A190836 A190837 * A190839 A190840 A190841

Keyword

nonn

Author

Zak Seidov, May 21 2011

Extensions

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

Status

approved