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 A127118 #12 Dec 28 2018 02:50:17 %S A127118 2,12,30,56,99,130,204,266,345,464,558,740,861,946,1128,1325,1534, %T A127118 1647,1876,2130,2336,2607,2822,3115,3492,3838,4017,4280,4578,4972, %U A127118 5715,6026,6576,6811,7450,7701,8164,8802,9185,9688,10203,10498,11460,11966,12411 %N A127118 a(n) = n-th prime * n-th nonprime. %H A127118 Harvey P. Dale, <a href="/A127118/b127118.txt">Table of n, a(n) for n = 1..1000</a> %F A127118 a(n) = A000040(n) * A018252(n). %t A127118 Module[{nn=100,prs,non,len},prs=Prime[Range[nn]];non=Complement[ Range[ nn],prs]; len=Min[Length[prs],Length[non]]; Times@@#&/@ Thread[ {Take[ prs,len],Take[non,len]}]] (* _Harvey P. Dale_, Dec 29 2012 *) %o A127118 (Haskell) %o A127118 a127118 n = a000040 n * a018252 n -- _Reinhard Zumkeller_, Apr 30 2014 %o A127118 (Python) %o A127118 from sympy import prime, composite %o A127118 def A127118(n): %o A127118 return 2 if n == 1 else prime(n)*composite(n-1) # _Chai Wah Wu_, Dec 27 2018 %Y A127118 Cf. A000040, A018252, A002808. %Y A127118 Cf. A014237, A064799, A067563. %K A127118 nonn,easy %O A127118 1,1 %A A127118 Neven Juric (neven.juric(AT)apis-it.hr), Mar 21 2007