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 A078323 #13 Apr 10 2025 05:24:52 %S A078323 1,1,7,6,15,1,45,1,32,1,63,1,129,1,115,14,213,1,183,70,281,102,381,34, %T A078323 165,1,43,134,423,70,581,18,773,102,615,38,969,459,763,1,957,358,1715, %U A078323 431,780,102,1847,34,524,170,1303,607,1977,155,1725,162,3825,678,1743 %N A078323 Arithmetic derivative of n*rad(n)+1, where rad = A007947 (squarefree kernel). %H A078323 Reinhard Zumkeller, <a href="/A078323/b078323.txt">Table of n, a(n) for n = 1..10000</a> %F A078323 a(n) = A003415(A078310(n)). %t A078323 ad[n_] := n * Plus @@ ((Last[#]/First[#]) & /@ FactorInteger[n]); a[n_] := ad[1 + n * Times @@ FactorInteger[n][[;;, 1]]]; Array[a, 100] (* _Amiram Eldar_, Apr 10 2025 *) %o A078323 (Haskell) %o A078323 a078323 = a003415 . a078310 -- _Reinhard Zumkeller_, Jul 23 2013 %Y A078323 Cf. A003415, A007947 (rad), A078310, A078322. %K A078323 nonn,easy %O A078323 1,3 %A A078323 _Reinhard Zumkeller_, Nov 23 2002