%I #19 Apr 30 2024 05:43:30
%S 887,1637,3089,3413,3947,5717,5903,5987,6803,7649,8243,8543,8783,8867,
%T 9257,10223,10433,10667,11027,11093,11177,11447,11597,11657,11867,
%U 11987,13127,13421,13649,14087,14177,15473,16943,17519,17807
%N Lower prime of a difference of 20 between consecutive primes.
%H Remi Eismann, <a href="/A031938/b031938.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Pri#gaps">Index entries for primes, gaps between</a>
%F a(n) = prime(A320708(n)). - _R. J. Mathar_, Apr 30 2024
%e 887 is a term as the next prime is 907.
%t (*M6*) a=887; S={}; Do[b=NextPrime[a]; If[b-a==20,AppendTo[S,a]]; a=b,{10^4}]; S [_Zak Seidov_, Aug 14 2009]
%t Transpose[Select[Partition[Prime[Range[2000]], 2, 1], Last[#] - First[#] == 20 &]][[1]] (* _Bruno Berselli_, Apr 09 2013 *)
%o (Magma) [p: p in PrimesUpTo(20000) | NextPrime(p)-p eq 20]; // _Bruno Berselli_, Apr 09 2013
%K nonn
%O 1,1
%A _Jeff Burch_
%E Entries and b-file checked by _Zak Seidov_, Aug 14 2009