This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A132860 #7 Jul 24 2024 02:06:16
%S A132860 2,0,93,119,531,897,1339,1341,1343,9569,15703,15705,19633,19635,31425,
%T A132860 31427,31429,31431,31433,155959,155961,155963,360697,360699,360701,
%U A132860 370311,370313,370315,370317,1349591,1357261,1357263,1357265,1357267
%N A132860 Smallest number at distance 2n from nearest prime (variant 2).
%C A132860 Let f(m) be the distance to the nearest prime as defined in A051699(m). Then a(n) = min { m: f(m)= 2n }. A051728 uses A051700(m) to define the distance.
%C A132860 Note that the requirement f(m)>=2n yields the same sequence as f(m)=2n here. (Reasoning: We are essentially probing for prime gaps of size 4n or larger while increasing m. One cannot get earlier hits by relaxing the requirement from the equal to the larger-or-equal sign, because m triggers as soon as the distance to the start of the gap reaches 2n, with both definitions. This is an inherent consequence of using A051699.)
%F A132860 a(n) = min {m : A051699(m) = 2n}.
%p A132860 A051699 := proc(m) if isprime(m) then 0 ; elif m <= 2 then op(m+1,[2,1]) ; else min(nextprime(m)-m,m-prevprime(m)) ; fi ; end: a := proc(n) local m ; for m from 0 do if A051699(m) = 2 * n then RETURN(m) ; fi ; od: end: seq(a(n),n=0..18);
%Y A132860 Cf. A051728, A051699.
%K A132860 nonn
%O A132860 1,1
%A A132860 _R. J. Mathar_, Nov 18 2007, Nov 30 2007