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 A355528 #9 Jul 13 2022 20:37:09 %S A355528 1,2,0,3,1,4,0,0,1,5,0,6,1,1,0,7,0,8,0,2,1,9,0,0,1,0,0,10,1,11,0,2,1, %T A355528 1,0,12,1,2,0,13,1,14,0,0,1,15,0,0,0,2,0,16,0,2,0,2,1,17,0,18,1,0,0,3, %U A355528 1,19,0,2,1,20,0,21,1,0,0,1,1,22,0,0,1,23 %N A355528 Minimal difference between adjacent 0-prepended prime indices of n > 1. %C A355528 A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798. %H A355528 Gus Wiseman, <a href="/A325325/a325325.txt">Sequences counting and ranking integer partitions by the differences of their successive parts</a>. %e A355528 The 0-prepended prime indices of 9842 are {0,1,4,8,12}, with differences (1,3,4,4), so a(9842) = 1. %t A355528 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A355528 Table[Min@@Differences[Prepend[primeMS[n],0]],{n,2,100}] %Y A355528 Crossrefs found in the link are not repeated here. %Y A355528 Positions of first appearances are 4 followed by A000040. %Y A355528 Positions of positive terms are A005117, complement A013929. %Y A355528 A similar statistic is counted by A238353. %Y A355528 The maximal version is A286469, without prepending A355526. %Y A355528 Without prepending we have A355524 or A355525. %Y A355528 Positions of ones are A355530. %Y A355528 A001522 counts partitions with a fixed point (unproved), ranked by A352827. %Y A355528 A112798 lists prime indices, with sum A056239. %Y A355528 A287352, A355533, A355534, A355536 list the differences of prime indices. %Y A355528 Cf. A064428, A066312, A091602, A120944, A238354, A286470, A325161, A352822, A355527, A355531, A355532. %K A355528 nonn %O A355528 2,2 %A A355528 _Gus Wiseman_, Jul 10 2022