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 A189762 #5 Mar 30 2012 17:22:58
%S A189762 0,6,10,14,0,22,26,0,34,38,0,46,27,0,58,62,0,0,74,42,82,86,0,94,63,0,
%T A189762 106,0,70,118,122,0,0,134,105,142,146,98,0,158,0,166,117,0,178,0,175,
%U A189762 0,194,130,202,206,0,214,218,154,226,0,245,138,171,0,0,254
%N A189762 Greatest integer x such that x' = 2n+1, or 0 if there is no such x, where x' is the arithmetic derivative (A003415).
%C A189762 Bisection of A099303. In contrast to the sequence for even numbers, A102084, there appear to be an infinite number of zeros in this sequence (see A098700). The density of the zeros appears to be 1/3. Quite Often a(n) = 4n-2. For odd number 2n+1, an upper bound on the largest anti-derivative x appears to ((2n+1)/3)^(3/2).
%H A189762 T. D. Noe, <a href="/A189762/b189762.txt">Table of n, a(n) for n = 1..10000</a>
%t A189762 dn[0] = 0; dn[1] = 0; dn[n_] := Module[{f = Transpose[FactorInteger[n]]}, If[PrimeQ[n], 1, Plus @@ (n*f[[2]]/f[[1]])]]; nn = 100; d = Array[dn, (nn/2)^2]; Table[pos = Position[d, n]; If[pos == {}, 0, pos[[-1, 1]]], {n, 3, nn, 2}]
%Y A189762 Cf. A003415, A099303, A102084 (another bisection of A099303).
%K A189762 nonn
%O A189762 1,2
%A A189762 _T. D. Noe_, Apr 27 2011