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 A077018 #9 Feb 16 2025 08:32:48
%S A077018 2,2,2,3,5,5,7,7,7,11,11,11,13,13,13,17,17,17,19,19,19,23,23,23,23,23,
%T A077018 29,29,29,29,31,31,31,31,37,37,37,37,37,41,41,41,43,43,43,47,47,47,47,
%U A077018 47,53,53,53,53,53,53,59,59,59,59,61,61,61,61,67,67,67,67,67,71,71,71
%N A077018 Closest prime to n (break ties by taking the larger prime).
%H A077018 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NearestPrime.html">Nearest Prime</a>
%t A077018 a[n_] := (np = NextPrime[n]; pp = NextPrime[np, -1]; Which[np > 2n - pp, pp, np < 2n - pp, np, True, np]); a[0] = a[1] = 2; Table[a[n], {n, 0, 71}] (* _Jean-François Alcover_, Oct 31 2012 *)
%Y A077018 This is the same as A051697 except that one of the 3s is deleted here.
%K A077018 nonn
%O A077018 0,1
%A A077018 _Eric W. Weisstein_, Oct 17 2002