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 A141275 #8 Jul 20 2025 08:59:56 %S A141275 5,17,23,41,73,97,103,113,131,137,151,173,211,229,277,317,337,347,367, %T A141275 421,439,463,499,503,523,557,601,631,647,677,691,727,769,827,857,881, %U A141275 887,907,911,1013,1021,1069,1087,1091,1103,1151,1201,1249,1303,1321 %N A141275 Composite indices associated with A141274. %t A141275 a141274=Select[Range[4,1600],!PrimeQ[#]&&PrimeQ[#+1]&&PrimeQ[#-PrimePi[#]-2]&];findx[n_]:=n-PrimePi[n]-2;findx/@a141274 (* _James C. McMahon_, Jul 19 2025 *) %Y A141275 Cf. A141274. %K A141275 easy,nonn %O A141275 1,1 %A A141275 _Enoch Haga_, Jun 21 2008 %E A141275 Edited by _N. J. A. Sloane_, Jun 21 2008