A304113 - OEIS

%I #8 May 17 2018 17:02:45

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

%T 4,9,4,2,4,5,7,5,4,2,4,12,5,5,7,7,3,5,13,4,4,9,4,2,4,9,4,2,4,14,15,5,

%U 4,2,4,5,9,5,12,4,2,4,8,13,4,7,4,2,4,13,4,4,10,5,4,2,4,16,5,4,7,9,5,9,14,4,2,4,9,9,12,5

%N Restricted growth sequence transform of A278263(n) = A046523(A064413(n)), a filter based on the prime signature of EKG-sequence.

%C For all i, j: a(i) = a(j) => A064742(i) = A064742(j).

%C For all i, j: a(i) = a(j) => A065203(i) = A065203(j).

%H Antti Karttunen, <a href="/A304113/b304113.txt">Table of n, a(n) for n = 1..65539</a>

%H <a href="/index/Ed#EKG">Index entries for sequences related to EKG sequence</a>

%o (PARI)

%o \\ Needs also code for A064413:

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

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

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

%o A278263(n) = A046523(A064413(n));

%o write_to_bfile(1,rgs_transform(vector(65539,n,A278263(n))),"b304113.txt");

%Y Cf. A046523, A064413, A064742, A065203, A278263, A304112.

%Y Cf. also A304115.

%K nonn

%O 1,2

%A _Antti Karttunen_, May 17 2018