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URL: https://oeis.org/A372571

⇱ A372571 - OEIS

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A372571
Lexicographically earliest infinite sequence such that a(i) = a(j) => A324198(i) = A324198(j) and A342671(i) = A342671(j), for all i, j >= 1.
1
1, 2, 3, 1, 1, 2, 1, 2, 3, 4, 1, 1, 1, 2, 5, 1, 1, 2, 1, 6, 3, 2, 1, 7, 8, 2, 9, 1, 1, 2, 1, 10, 3, 2, 11, 1, 1, 2, 3, 12, 1, 13, 1, 2, 5, 2, 1, 1, 11, 14, 3, 1, 1, 7, 15, 13, 9, 2, 1, 16, 1, 2, 17, 1, 18, 2, 1, 10, 3, 19, 1, 7, 1, 2, 20, 1, 11, 2, 1, 4, 3, 2, 1, 11, 15, 2, 9, 10, 1, 2, 11, 2, 3, 2, 1, 10, 1, 21, 22, 23, 1, 2, 1, 2
OFFSET
1,2
COMMENTS
Restricted growth sequence transform of the ordered pair [A324198(n), A342671(n)].
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; };
A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A324198(n) = { my(m=1, p=2, orgn=n); while(n, m *= (p^min(n%p, valuation(orgn, p))); n = n\p; p = nextprime(1+p)); (m); };
Aux372571(n) = [A324198(n), gcd(sigma(n), A003961(n))];
v372571 = rgs_transform(vector(up_to, n, Aux372571(n)));
A372571(n) = v372571[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 24 2024
STATUS
approved