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.

A322592 Lexicographically earliest such sequence a that for all i, j, a(i) = a(j) => f(i) = f(j), where f(n) = 0 for odd primes, and f(n) = A289625(n) for any other number.

Original entry on oeis.org

1, 1, 2, 3, 2, 3, 2, 4, 5, 6, 2, 4, 2, 5, 7, 7, 2, 5, 2, 7, 8, 9, 2, 10, 11, 12, 13, 8, 2, 7, 2, 14, 15, 16, 17, 8, 2, 13, 17, 18, 2, 8, 2, 15, 17, 19, 2, 18, 20, 11, 21, 17, 2, 13, 22, 23, 24, 25, 2, 18, 2, 26, 27, 21, 28, 15, 2, 21, 29, 17, 2, 23, 2, 30, 22, 24, 31, 17, 2, 32, 33, 34, 2, 23, 35, 20, 36, 37, 2, 17, 38, 29, 31, 39, 40, 41, 2, 20, 31, 22, 2, 21, 2, 42, 42
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2018

Keywords

Comments

For all i, j:
a(i) = a(j) => A034380(i) = A034380(j),
a(i) = a(j) => A104194(i) = A104194(j),
a(i) = a(j) => A290084(i) = A290084(j).

Crossrefs

Programs

  • PARI
    default(parisizemax,2^31);
    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; };
    A289625(n) = { my(m=1,p=2,v=znstar(n)[2]); for(i=1,length(v),m *= p^v[i]; p = nextprime(p+1)); (m); };
    Aux322592(n) = if((n>2)&&isprime(n),0,A289625(n));
    v322592 = rgs_transform(vector(up_to, n, Aux322592(n)));
    A322592(n) = v322592[n];
    for(n=1,up_to,write("b322592.txt", n, " ", A322592(n)));