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Initial primes in sets of 4 consecutive primes with common gap 54.
9

%I #18 Oct 27 2018 09:20:54

%S 400948369,473838319,583946599,678953059,816604199,972598819,

%T 1136526949,1466715139,1475790529,1499794999,1502149559,1610895679,

%U 1643313869,1673057219,1686181579,1845792019,1867046639,1907478889,1992202439,2011077869,2030490479,2207714969

%N Initial primes in sets of 4 consecutive primes with common gap 54.

%C All terms are == {19,29} mod 30.

%H Lars Blomberg, <a href="/A259224/b259224.txt">Table of n, a(n) for n = 1..10000</a> (The first 102 terms from Zak Seidov)

%o (PARI) A259224(n, p=2, v=1, g=54, c, o)={forprime(q=p+1, , if(p+g!=p=q, next, q!=o+2*g, c=2, c++>3, v&& print1(o-g", "); n--||break); o=q-g); o-g} \\ Can be used as next(p)=A259224(1,p+1) to get the next term, e.g.:

%o p=0; A259224_vec=vector(10,i,p=A259224(1,p+1)) \\ Will be slow! - _M. F. Hasler_, Oct 26 2018

%Y Start of CPAP-4 with given common difference (in square brackets): A033451 [6], A033447 [12], A033448 [18], A052242 [24], A052243 [30], A058252 [36], A058323 [42], A067388 [48], A259224 [this: 54], A210683 [60].

%Y Subsequence of A054800: start of a CPAP-4 with arbitrary common difference.

%K nonn

%O 1,1

%A _Zak Seidov_, Jun 21 2015