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A094382 Number of quadruples (p, p+d, p+2*d, p+3*d) of primes with d>0 and p+3*d<=n. 1

%I

%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,2,2,2,2,2,2,

%T 2,2,2,2,2,2,3,3,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,7,7,7,7,7,7,7,7,7,7,

%U 7,7,7,7,7,7,7,7,7,7,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9,9,11,11,11,11

%N Number of quadruples (p, p+d, p+2*d, p+3*d) of primes with d>0 and p+3*d<=n.

%H <a href="/index/Pri#primes_AP">Index entries for sequences related to primes in arithmetic progressions</a>

%e a(50)=4: 5=prime(3) -> 5+6=11=prime(5) -> 11+6=17=prime(7) ->

%e 17+6=23=prime(9), 5=prime(3) -> 5+12=17=prime(7) -> 17+12=29=prime(10) ->

%e 29+12=41=prime(13), 7=prime(4) -> 7+12=19=prime(8) -> 19+12=31=prime(11) ->

%e 31+12=43=prime(14) and 11=prime(5) -> 11+6=17=prime(7) -> 17+6=23=prime(9)

%e -> 23+6=29=prime(10),

%Y Cf. A093354, A094383.

%K nonn

%O 1,29

%A _Reinhard Zumkeller_, Apr 28 2004

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Last modified April 3 16:46 EDT 2020. Contains 333197 sequences. (Running on oeis4.)