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 A171575 #10 Mar 08 2018 12:05:05
%S A171575 1,6,9,13,17,23,27,33,37,43,51,55,63,69,73,79,87,95,99,107,113,117,
%T A171575 125,131,139,149,155,159,165,169,175,191,197,205,209,221,225,233,241,
%U A171575 247,255,263,267,279,283,289,293,307,321,327,331,337,345,349,361,369,377
%N A171575 n-th noncomposite number plus n-th even nonprime number.
%F A171575 a(n) = A008578(n) + A163300(n).
%e A171575 a(1) = 1 + 0 = 1, a(2) = 2 + 4 = 6, a(3) = 3 + 6 = 9.
%t A171575 Module[{nc=Select[Range[300],!CompositeQ[#]&],len},len=Length[nc];Join[ {1},Rest[Total/@Thread[{nc,Range[2,2len,2]}]]]] (* _Harvey P. Dale_, Mar 08 2018 *)
%Y A171575 Cf. A008578(the noncomposite numbers), A163300(the even nonprime numbers).
%K A171575 nonn
%O A171575 1,2
%A A171575 _Juri-Stepan Gerasimov_, Dec 12 2009
%E A171575 Entries checked by _R. J. Mathar_, May 23 2010