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 A064168 #24 Sep 07 2019 07:04:29 %S A064168 2,5,17,37,197,69,503,1041,9649,9901,111431,113741,1506353,1532093, %T A064168 1556117,3157279,54394463,18358381,352893319,71354639,24031221, %U A064168 24266365,563299563,1704771547,42976237267,43319457067,392849685203,395718022103,11556136074187 %N A064168 Sum of numerator and denominator in n-th harmonic number, 1 + 1/2 + 1/3 +...+ 1/n. %C A064168 Numerator and denominator in definition have no common factors >1. %H A064168 Brian Hayes, <a href="http://bit-player.org/2017/a-tantonalizing-problem">A Tantonalizing Problem</a> %e A064168 The 3rd harmonic number is 11/6. So a(3) = 11 + 6 = 17. %p A064168 h:= n-> numer(sum(1/k,k=1..n))+denom(sum(1/k,k=1..n)): seq(h(n),n=1..30); # _Emeric Deutsch_, Nov 18 2004 %t A064168 Numerator[#]+Denominator[#]&/@HarmonicNumber[Range[30]] (* _Harvey P. Dale_, Jul 04 2017 *) %o A064168 (PARI) a(n) = my(h=sum(k=1, n, 1/k)); numerator(h) + denominator(h); \\ _Michel Marcus_, Sep 07 2019 %Y A064168 Cf. A001008, A002805, A064167, A064169. %K A064168 nonn,easy %O A064168 1,1 %A A064168 _Leroy Quet_, Sep 19 2001 %E A064168 More terms from _Emeric Deutsch_, Nov 18 2004