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 A099984 #12 Nov 19 2022 04:45:01
%S A099984 1,3,5,7,3,11,13,15,17,19,21,23,5,3,29,31,33,35,37,39,41,43,15,47,7,
%T A099984 51,53,55,57,59,61,21,65,67,69,71,73,15,77,79,3,83,85,87,89,91,93,95,
%U A099984 97,33,101,103,105,107,109,111,113,115,39,119,11,123,5,127,129,131,133,15,137
%N A099984 Bisection of A007947.
%H A099984 Amiram Eldar, <a href="/A099984/b099984.txt">Table of n, a(n) for n = 1..10000</a>
%F A099984 From _Amiram Eldar_, Nov 19 2022: (Start)
%F A099984 a(n) = A007947(2*n-1).
%F A099984 Sum_{k=1..n} a(k) ~ c * n^2, where c = (6/5) * Product_{p prime} (1 - 1/(p*(p+1))) = (6/5) * A065463 = 0.8453306... . (End)
%p A099984 with(numtheory): A007947 := proc(n) local i,t1,t2; t1 :=ifactors(n)[2]; t2 := mul(t1[i][1],i=1..nops(t1)); end: seq(A007947(2*n-1),n=1..78); # _Emeric Deutsch_, Dec 15 2004
%t A099984 a[n_] := Times @@ (First /@ FactorInteger[2*n-1]); Array[a, 100] (* _Amiram Eldar_, Nov 19 2022*)
%o A099984 (PARI) a(n) = factorback(factorint(2*n-1)[, 1]); \\ _Amiram Eldar_, Nov 19 2022
%Y A099984 Cf. A007947, A065463, A099985.
%K A099984 nonn,easy
%O A099984 1,2
%A A099984 _N. J. A. Sloane_, Nov 19 2004
%E A099984 More terms from _Emeric Deutsch_, Dec 15 2004
%E A099984 Offset corrected by _Amiram Eldar_, Nov 19 2022