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%I #13 Apr 24 2021 04:15:05
%S 4,4,8,4,8,12,4,12,8,4,8,4,20,4,20,4,8,12,12,4,12,12,8,12,12,4,12,12,
%T 12,8,12,24,4,20,16,12,8,12,4,36,12,8,4,20,4,12,8,4,8,4,20,24,16,8,16,
%U 12,8,12,12,12,4,12,24,8,28,8,12,4,8,36,24,12,4,12,20,4,20,4,20,4,8,28,20,4
%N First differences of primes of the form 4*k+3 (A002145).
%H Amiram Eldar, <a href="/A082075/b082075.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A002145(n+1) - A002145(n).
%e The first and second primes of the form 4*k+3 are 3 and 7, so a(1) = 7-3 = 4.
%t k=0; m=4; r=3; Do[s=Mod[Prime[n], m]; If[Equal[s, r], rp=ep; k=k+1; ep=Prime[n]; Print[ep-rp]; ], {n, 1, 1000}]
%Y Cf. A002144, A002145, A082073, A082074, A082075, A082076.
%K nonn
%O 1,1
%A _Labos Elemer_, Apr 07 2003