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 A378814 #22 Dec 17 2024 13:04:07 %S A378814 1,1,2,4,3,3,4,4,2,10,6,6,7,4,8,8,4,9,6,10,11,11,12,12,6,4,14,14,7,15, %T A378814 31,16,17,17,18,6,19,19,20,10,10,21,22,22,8,46,12,12,25,25,26,26,9,9, %U A378814 28,28,29,15,30,30,31,31,32,32,9,11,34,34,17,18,36 %N A378814 a(n) = round(n/(A000005(A071904(n))-2)). %C A378814 Nearly all of the data falls on lines discussed below. There are a few "outliers" visible on the graph. There are <120 such outliers in the first 20000 terms (about 0.6%). Many of the outlier indices belong to A037040. The lines are n, (n+0)/2, (n+2)/4, (n+4)/6, (n+6)/8,.... %H A378814 Paolo Xausa, <a href="/A378814/b378814.txt">Table of n, a(n) for n = 1..10000</a> %H A378814 Bill McEachen, <a href="/A378814/a378814.png">Plot 20K terms</a> %H A378814 Bill McEachen, <a href="/A378814/a378814_1.png">A037040 overlap (TEMP)</a> %e A378814 Let n=14, A071904(n)=63, tau(63)=6 so a(14)=round(14/(6-2))=4. %t A378814 MapIndexed[Floor[#2[[1]]/# + 1/2] &, DivisorSigma[0, Select[Range[9, 500, 2], CompositeQ]] - 2] (* _Paolo Xausa_, Dec 16 2024 *) %Y A378814 Cf. A000005, A037040, A071904. %K A378814 nonn %O A378814 1,3 %A A378814 _Bill McEachen_, Dec 08 2024