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A332826
Lexicographically earliest infinite sequence such that a(i) = a(j) => A046523(A332824(i)) = A046523(A332824(j)) for all i, j.
3
1, 2, 3, 4, 3, 5, 6, 7, 7, 5, 6, 8, 6, 9, 10, 11, 3, 12, 6, 13, 13, 9, 10, 14, 7, 9, 15, 16, 10, 17, 18, 19, 19, 5, 19, 20, 6, 9, 19, 21, 6, 22, 10, 23, 24, 17, 18, 25, 19, 12, 10, 23, 10, 26, 19, 27, 19, 17, 18, 28, 18, 29, 30, 31, 19, 32, 6, 13, 33, 32, 10, 34, 6, 9, 33, 23, 35, 32, 18, 36, 37, 9, 10, 38, 10, 17, 33, 39, 10, 40, 41, 39, 42, 29, 43, 44, 6, 32, 39, 45, 10, 17, 18, 39, 39
OFFSET
1,2
LINKS
PROG
(PARI)
up_to = 65537;
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; };
A019565(n) = {my(j, v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ From A019565
A332824(n) = { my(m=1); fordiv(n, d, m *= A019565(eulerphi(d))); (m); };
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
v332826 = rgs_transform(vector(up_to, n, A046523(A332824(n))));
A332826(n) = v332826[n];
CROSSREFS
Cf. A019434 (positions of 3's).
Cf. also A318835.
Sequence in context: A160180 A319351 A323373 * A353840 A319350 A336855
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 25 2020
STATUS
approved