login
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
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
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
Sequence in context: A151812 A224585 A190819 * A237072 A232122 A232420
KEYWORD
nonn
AUTHOR
Zak Seidov, May 21 2011
EXTENSIONS
Additional cross references from Harvey P. Dale, May 10 2014
STATUS
approved