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%I #12 Jan 24 2020 12:13:55
%S 1,1,1,2,4,1,1,2,2,2,2,3,1,3,1,2,2,4,1,1,2,2,2,2,2,2,5,2,12,1,5,1,1,1,
%T 2,4,1,1,4,2,18,4,1,1,2,2,2,4,1,1,2,6,1,1,1,1,4,2,6,3,1,2,3,3,4,4,1,3,
%U 8,2,2,6,1,1,1,3,6,2,2,2,3,6,6,1,1,1,3,8,12
%N Distance between n and the next number with the same number of distinct prime factors.
%H Robert Israel, <a href="/A188348/b188348.txt">Table of n, a(n) for n = 2..10000</a>
%F {min d>0: A001221(n+d) = A001221(n)}.
%p N:= 200: # to use numbers up to N
%p V:= Array(2..N, n -> nops(numtheory:-factorset(n))):
%p A:= Array(2..N):
%p for n from 2 to N do
%p v:= V[n];
%p if assigned(Last[v]) then
%p A[Last[v]]:= n-Last[v]
%p fi;
%p Last[v]:= n;
%p od:
%p m:= min(select(t -> A[t]=0, [$2..N]))-1:
%p seq(A[i],i=2..m); # _Robert Israel_, Jan 24 2020
%o (PARI) for(n=2, 100, f=omega(n); m=n+1; while(omega(m)!=f, m++); print1(m-n, ", ")) \\ _Colin Barker_, Jun 27 2014
%Y Cf. A001221, A178139.
%K nonn
%O 2,4
%A _Juri-Stepan Gerasimov_, Mar 28 2011
%E Renamed, edited and checked by R. J. Mathar, Mar 28 2011.
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