OFFSET
1,2
COMMENTS
This sequence gives the index of A055625(n) after sorting by increasing magnitude.
LINKS
J. K. Andersen, Consecutive Congruent Primes.
Hugo Pfoertner, Record producing runs of primes of the forms 6k+-1
Hugo Pfoertner, FORTRAN function ISPRIM to check primality.
EXAMPLE
a(3)=3, a(4)=6, a(5)=4 because the first occurrence of exactly 6 consecutive primes of the form 6*k+1 (1741,1747,1753,1759,1777,1783) occurs after the first occurrence of 3 consecutive primes of this form (151,157,163) and before the first occurrence of 4 consecutive "6k+1"-primes (3049,3061,3067,3079).
MATHEMATICA
(* Program not suitable to compute a large number of terms. *)
pp = Table[{p = Prime[n], Mod[p, 6]}, {n, 10^7}];
sp = Split[pp, Mod[#1[[2]], 6] == Mod[#2[[2]], 6]&];
b[n_] := SelectFirst[sp, Length[#] == n && MatchQ[#, {{_Integer, 1} ..}]& ][[1, 1]];
Sort[Table[{b[n], n}, {n, 1, 16}]][[All, 2]] (* Jean-François Alcover, Nov 21 2018 *)
PROG
FORTRAN program given at link.
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Hugo Pfoertner, Jul 31 2003
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 27 2006
a(32)-a(35) from Giovanni Resta, Aug 04 2013
STATUS
approved