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 A099072 #7 Dec 23 2024 01:54:43 %S A099072 1,2,3,3,4,6,5,7,8,6,9,12,7,17,13,8,15,18,9,21,19,6,30,11,24,19,23,18, %T A099072 30,27,22,18,42,11,30,42,9,39,36,30,19,56,6,48,57,13,44,46,17,45,69, %U A099072 13,41,49,56,27,85,18,30,84,26,64,26,64,47,54,45,94,17,36,85,60,23,79,98 %N A099072 First differences of A000960, divided by 2. %F A099072 a(n) = A073359(n+1) - A073359(n), (conjectured, n>1). - _Bill McEachen_, Dec 22 2024 %t A099072 del[lst_, k_] := lst[[ Select[ Range[ Length[ lst]], Mod[ #, k] != 0 &]]]; For[ k = 2; s = Range[10000], k <= Length[s], k++, s = del[s, k]]; (Drop[s, 1] - Drop[s, -1])/2 %Y A099072 Cf. A000960, A056526. %K A099072 nonn,easy %O A099072 1,2 %A A099072 _N. J. A. Sloane_, Nov 15 2004 %E A099072 More terms from _Robert G. Wilson v_, Nov 15 2004