A365393 - OEIS

A365393

Lexicographically earliest infinite sequence such that a(i) = a(j) => A364492(i) = A364492(j) for all i, j >= 0, where A364492(n) is the denominator of n / A163511(n).

1, 2, 2, 1, 2, 3, 1, 4, 2, 5, 3, 6, 1, 7, 4, 8, 2, 9, 5, 10, 3, 6, 6, 11, 1, 3, 7, 12, 4, 13, 8, 14, 2, 9, 9, 10, 5, 15, 10, 16, 3, 17, 6, 18, 6, 11, 11, 19, 1, 20, 3, 21, 7, 22, 12, 8, 4, 13, 13, 23, 8, 24, 14, 25, 2, 26, 9, 27, 9, 28, 10, 29, 5, 30, 15, 16, 10, 31, 16, 32, 3, 6, 17, 33, 6, 31, 18, 34, 6, 35, 11

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OFFSET

0,2

COMMENTS

Restricted growth sequence transform of A364492.

Question: Which sets of numbers cause the finite branches that grow off-angle from the rays emanating from the origin in the scatter plot, and why the sudden bends in some of them? Compare also to the scatter plot of A365431.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..65537

FORMULA

For all n >= 1, a(n) = a(2*n) = a(A000265(n)).

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; };

A163511(n) = if(!n, 1, my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));

A364492(n) = { my(u=A163511(n)); (u/gcd(n, u)); };

v365393 = rgs_transform(vector(1+up_to, n, A364492(n-1)));

A365393(n) = v365393[1+n];

CROSSREFS

Cf. A000265, A003602, A163511, A364255, A364492.

Cf. also A365384, A365431.

Sequence in context: A321325 A233918 A071694 * A366286 A072781 A340094

Adjacent sequences: A365390 A365391 A365392 * A365394 A365395 A365396

KEYWORD

nonn,look

AUTHOR

Antti Karttunen, Sep 06 2023

STATUS

approved