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 A100005 #9 Aug 17 2019 08:04:19 %S A100005 0,3,5,7,6,11,13,8,17,19,10,23,10,9,29,31,14,12,37,16,41,43,11,47,14, %T A100005 20,53,16,22,59,61,13,18,67,26,71,73,13,18,79,12,83,22,32,89,20,34,24, %U A100005 97,17,101,103,15,107,109,40,113,28,19,24,22,44,15,127,46,131,26,14,137 %N A100005 Bisection of A001414. %C A100005 Integer log of (2n-1): sum of primes dividing 2n-1 (with repetition). - _Emeric Deutsch_, Mar 10 2005 %e A100005 a(23)=11 because 45=3^2*5^1 and 2*3+1*5=11. %p A100005 with(numtheory): a:=proc(n) local b: b:=op(2,ifactors(n)): sum(b[j][1]*b[j][2],j=1..nops(b)): end: seq(a(2*n-1),n=1..78); # _Emeric Deutsch_, Mar 10 2005 %K A100005 nonn,easy %O A100005 1,2 %A A100005 _N. J. A. Sloane_, Nov 20 2004 %E A100005 More terms from _Emeric Deutsch_, Mar 10 2005