cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A329045 Lexicographically earliest infinite sequence such that a(i) = a(j) => A046523(A329044(i)) = A046523(A329044(j)) for all i, j.

Original entry on oeis.org

1, 2, 2, 3, 2, 3, 2, 4, 4, 3, 2, 5, 2, 3, 6, 7, 2, 7, 2, 5, 6, 3, 2, 8, 9, 3, 4, 5, 2, 10, 2, 4, 6, 3, 11, 12, 2, 3, 6, 4, 2, 4, 2, 5, 10, 3, 2, 8, 13, 14, 6, 5, 2, 7, 9, 15, 6, 3, 2, 16, 2, 3, 16, 7, 17, 18, 2, 5, 6, 19, 2, 20, 2, 3, 21, 5, 22, 18, 2, 7, 13, 3, 2, 7, 23, 3, 6, 15, 2, 24, 25, 5, 6, 3, 26, 27, 2, 28, 24, 13, 2, 18, 2, 15, 29
Offset: 1

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Author

Antti Karttunen, Nov 08 2019

Keywords

Comments

Restricted growth sequence transform of function f(n) = A046523(A329044(n)).
For all i, j:
A305800(i) = A305800(j) => a(i) = a(j),
a(i) = a(j) => A324888(i) = A324888(j),
a(i) = a(j) => A329046(i) = A329046(j).

Crossrefs

Programs

  • 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; };
    A034386(n) = prod(i=1, primepi(n), prime(i));
    A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) };  \\ From A108951
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A324886(n) = A276086(A108951(n));
    A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
    A329044(n) = A064989(A324886(n));
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
    v329045 = rgs_transform(vector(up_to, n, A046523(A329044(n))));
    A329045(n) = v329045[n];