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A303779 Restricted growth sequence transform of A278222(A303775(n)). 4

%I #6 May 12 2018 14:44:12

%S 1,2,3,2,3,2,4,5,6,5,3,2,7,4,7,4,6,2,4,7,4,8,4,9,10,7,11,7,3,2,11,7,4,

%T 12,13,7,4,6,5,3,8,7,11,7,14,15,8,5,4,10,8,4,12,7,8,7,8,7,13,9,15,9,

%U 13,9,13,2,16,9,4,13,9,4,17,9,4,13,7,18,13,7,4,13,9,19,15,8,4,17,9,8,7,8,9,13,15,13,7,11,7,3,11,7,12,13,7

%N Restricted growth sequence transform of A278222(A303775(n)).

%H Antti Karttunen, <a href="/A303779/b303779.txt">Table of n, a(n) for n = 0..65537</a>

%F For all i, j: a(i) = a(j) => A303780(i) = A303780(j).

%o (PARI)

%o \\ Needs also code from A303775:

%o rgs_transform(invec) = { my(occurrences = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(occurrences,invec[i]), my(pp = mapget(occurrences, invec[i])); outvec[i] = outvec[pp] , mapput(occurrences,invec[i],i); outvec[i] = u; u++ )); outvec; };

%o write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }

%o A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };

%o A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523

%o A278222(n) = A046523(A005940(1+n));

%o write_to_bfile(0,rgs_transform(vector(65538,n,A278222(A303775(n-1)))),"b303779.txt");

%Y Cf. A278222, A303775, A303780.

%Y Cf. also A286602, A302795, A304088.

%K nonn

%O 0,2

%A _Antti Karttunen_, May 06 2018

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