%I A071182
%S A071182 1,1,3,3,5,5,1,1,9,9,11,11,1,1,15,15,17,17,1,1,21,21,3,3,1,1,27,27,29,
%T A071182 29,1,1,3,3,35,35,1,1,39,39,41,41,1,1,45,45,5,5,1,1,51,51,3,3,1,1,57,
%U A071182 57,59,59,1,1,3,3,65,65,1,1,69,69,71,71,1,1,5,5,77,77,1,1,81,81,3,3,1
%V A071182 1,-1,3,-3,5,-5,1,-1,9,-9,11,-11,1,-1,15,-15,17,-17,1,-1,21,-21,3,-3,1,
               -1,27,-27,29,
%W A071182 -29,1,-1,3,-3,35,-35,1,-1,39,-39,41,-41,1,-1,45,-45,5,-5,1,-1,51,-51,
               3,-3,1,-1,57,
%X A071182 -57,59,-59,1,-1,3,-3,65,-65,1,-1,69,-69,71,-71,1,-1,5,-5,77,-77,1,-1,
               81,-81,3,-3,1
%N A071182 SPF(n+1)-SPF(n), where SPF(n) denotes the smallest prime factor of n.
%t A071182 g[n_] := (FactorInteger[n])[[1]][[1]]; f[n_] := g[n + 1] - g[n]; Table[f[i], 
               {i, 2, 100}]
%Y A071182 Sequence in context: A087852 A087853 A095334 this_sequence A136027 A133772 
               A129972
%Y A071182 Adjacent sequences: A071179 A071180 A071181 this_sequence A071183 A071184 
               A071185
%K A071182 sign
%O A071182 2,3
%A A071182 Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Jun 10 2002