login
Initial prime of exactly nine consecutive primes congruent to 1 modulo 4.
3

%I #8 Nov 21 2013 12:49:39

%S 11593,206953,315257,541097,906541,992393,1124993,1410361,1595081,

%T 1781569,1872049,2043329,2090353,2312749,2381657,2481509,2497289,

%U 2718389,2758109,2772409,2976397,3863473,3868849,4027957,4042673

%N Initial prime of exactly nine consecutive primes congruent to 1 modulo 4.

%C The table provides all 8919 [=A092660(9)] terms less than 10^9.

%C If 10 or more consecutive primes are all congruent to 1 modulo 4, none of them is a member of this sequence. [From Harvey P. Dale, Oct 23 2011]

%H Rick L. Shepherd, <a href="/A162865/b162865.txt">Table of n, a(n) for n=1..8919</a>

%t m9Q[l_]:=Module[{ms=Mod[l,4]},First[ms]!=1&&Last[ms]!=1&&Union[Take[ ms,{2,10}]]=={1}]; Transpose[Select[Partition[ Prime[Range[ 290000]], 11,1],m9Q]][[2]] (* _Harvey P. Dale_, Oct 23 2011 *)

%Y Cf. A092660, A162866, A055623, A057624, A054678.

%K nonn

%O 1,1

%A _Rick L. Shepherd_, Jul 15 2009