OFFSET
1,1
COMMENTS
a(n) + 30 is the greatest term in the sequence of 6 consecutive primes with consecutive gaps 2, 4, 6, 8, 10. - Muniru A Asiru, Aug 10 2017
LINKS
Zak Seidov, Table of n, a(n) for n = 1..6000
R. J. Mathar, Table of Prime Gap Constellations
EXAMPLE
For n = 1, 13901 is in the sequence because 13901, 13903, 13907, 13913, 13921, 13931 are consecutive primes and for n = 2, 21557 is in the sequence since 21557, 21559, 21563, 21569, 21577, 21587 are consecutive primes. - Muniru A Asiru, Aug 24 2017
MAPLE
N:=10^7: # to get all terms <= N.
Primes:=select(isprime, [seq(i, i=3..N+30, 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]]=[2, 4, 6, 8, 10], [$1..nops(Primes)-5])]; # Muniru A Asiru, Aug 04 2017
MATHEMATICA
d = Differences[Prime[Range[100000]]]; Prime[Flatten[Position[Partition[d, 5, 1], {2, 4, 6, 8, 10}]]] (* T. D. Noe, May 23 2011 *)
With[{s = Differences@ Prime@ Range[10^6]}, Prime[SequencePosition[s, Range[2, 10, 2]][[All, 1]] ] ] (* Michael De Vlieger, Aug 16 2017 *)
PROG
(PARI) lista(nn) = forprime(p=13901, nn, if(nextprime(p+1)==p+2 && nextprime(p+3)==p+6 && nextprime(p+7)==p+12 && nextprime(p+13)==p+20 && nextprime(p+21)==p+30, print1(p", "))); \\ Altug Alkan, Aug 16 2017
(GAP)
K:=3*10^7+1;; # to get all terms <= K.
P:=Filtered([1, 3..K], IsPrime);; I:=[2, 4, 6, 8, 10];;
P1:=List([1..Length(P)-1], i->P[i+1]-P[i]);;
P2:=List([1..Length(P)-Length(I)], i->[P1[i], P1[i+1], P1[i+2], P1[i+3], P1[i+4]]);;
P3:=List(Positions(P2, I), i->P[i]); # Muniru A Asiru, Aug 24 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, May 21 2011
EXTENSIONS
Additional cross references from Harvey P. Dale, May 10 2014
STATUS
approved