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 A103416 #12 Jul 30 2022 08:19:50
%S A103416 -1,0,0,1,1,2,2,3,4,4,5,5,6,7,8,8,9,10,10,11,12,13,13,14,15,15,16,17,
%T A103416 18,19,19,20,21,22,22,23,24,25,26,26,27,28,29,30,30,31,32,33,33,34,35,
%U A103416 36,37,38,38,39,40,41,42,43,44,44,45,46,47,48,48,49,50,51,52,53,53,54,55
%N A103416 a(n) = n - ceiling(sqrt(prime(n))).
%F A103416 a(n) = n - A104103(n). - _Michel Marcus_, Jul 30 2022
%t A103416 Table[n - Ceiling[ Sqrt[ Prime[ n]]], {n, 75}] (* _Robert G. Wilson v_, Mar 24 2005 *)
%o A103416 (Python)
%o A103416 from math import isqrt
%o A103416 from sympy import prime
%o A103416 def A103416(n): return n-isqrt(prime(n+1)) # _Chai Wah Wu_, Jul 29 2022
%Y A103416 Cf. A104103.
%K A103416 sign
%O A103416 0,6
%A A103416 _Giovanni Teofilatto_, Mar 21 2005
%E A103416 More terms from _Robert G. Wilson v_, Mar 24 2005