%I #10 Oct 27 2013 05:01:15
%S 3,19,41,43,71,83,101,109,151,167,199,227,229,257,281,283,311,313,349,
%T 383,401,443,461,463,487,503,571,601,617,641,643,677,727,757,829,857,
%U 859,881,883,911,937,941,971,1033,1063,1091,1093,1123,1187,1217,1231
%N Primes occurring twice in A051701.
%C Consider five consecutive primes p1..p5: (p3 is a term of this sequence) iff (p2-p1 > p3-p2 and p5-p4 > p4-p3).
%H Reinhard Zumkeller, <a href="/A227878/b227878.txt">Table of n, a(n) for n = 1..10000</a>
%o (Haskell)
%o a227878 n = a227878_list !! (n-1)
%o a227878_list = f a051701_list where
%o f (p:ps@(_:p':_)) = if p == p' then p : f ps else f ps
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Oct 25 2013
|