

A190838


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


12



128981, 21456047, 34864211, 51867197, 55793951, 69726647, 113575727, 180078317, 207664397, 232728647, 342241967, 382427027, 382533311, 470463011, 558791327, 591360851, 603413801, 749930717, 838115711, 926976431, 965761397, 1007421251, 1109867567, 1278189947
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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(qpt==2, t+=2; if(t==14, listput(v, q56); 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



